Upit | Learn about creating the game Piano Peng with gen AI

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Piano Peng

octo

PianoPeng

Playit

Master the music to save the princess.

#RhythmGame

##UpitMusicContest

Creation History

User prompt

create a new asset named coin and place one in every empty cell where the player can move, so when the player lands on that cell, it collects it

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remove anu legacy jump logic from the codee, if any

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please add a special sound effect for each beat which plays when the sequencer passes it. each beat should have a sound of it's own. name down Sound_Down, Sound_Up, Sound_Left, Sound_Right

User prompt

please add a special sound effect for each beat which plays when the sequencer passes it

Code edit (3 edits merged)

Please save this source code

User prompt

Hey Ava, You are an excellent developer. You followed my previous instructions to the letter, and the logic inside the SequencerService is now 100% correct for handling the beat after the game gets going. I'm sorry for sending you down the wrong path—the bug is more subtle than I first realized. We need to tell the game to draw the highlight for the first beat immediately when the game starts, without waiting for the sequencer's timer. The fix is incredibly simple and clean. Go to the very bottom of the script, to the INITIALIZE & RUN GAME section. Look right after all the .initialize() calls are finished. Add one new line of code to manually draw the very first highlight state before the game loop takes over. Your initialization section should look like this: // ... (all the service instantiations) ... // 3. Initialize Services in correct order uiService.initialize(); gridService.initialize(); playerService.initialize(); sequencerService.initialize(); // ---> ADD THIS LINE <--- // Manually draw the highlight for the first beat (step 0) immediately. uiService.updateColumnHighlight(sequencerService.currentStep); // 4. Connect Input Handlers to the Input Service game.down = function (x, y) { inputService.handleDown(x, y); }; // ... (rest of the code) ...

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Your SequencerService.update method's if block should look like this when you're done: // Inside SequencerService.update... if (this.playing && now - this.lastStepTime >= GameConstants.STEP_INTERVAL) { this.lastStepTime = now; // 1. UPDATE HIGHLIGHT FIRST for the current step this.uiService.updateColumnHighlight(this.currentStep); // 2. THEN, advance the step to the next beat this.currentStep = (this.currentStep + 1) % GameConstants.GRID_COLS; // 3. FINALLY, perform actions for the new step. this.doStepActions(); } Use code with caution. JavaScript With these two changes, the game will now: Draw a highlight on the column that's about to play. A fraction of a second later, the beat "hits," the step counter advances, and the hero performs the action for that highlighted column.

User prompt

Go to the game.update function at the bottom of the script. Delete this line: uiService.updateColumnHighlight(sequencerService.currentStep); The game.update function should now only contain one line: sequencerService.update();. This ensures the SequencerService has full control over the timing. Step 2: Correct the Order of Operations in the Sequencer Now for the main fix. We need to change the sequence of events inside SequencerService.update. The current, incorrect order is: Advance step. Do actions. Update highlight. The new, correct order should be: Update highlight for the current step (to show what's about to happen). Advance step to the next step. Do actions for the newly advanced step. Here's how to change the code in SequencerService.update: Move the highlight call to the TOP of the if block. Keep the currentStep advancement in the middle.

User prompt

The Sequencer only knows about timing, the GridService only knows about cell states, and the UIService handles all the visual representation, including the complex new highlighting rule. however this isn't the case as I still can't see the new implementation of the sequencer, cells are not being highlighted

User prompt

Connect Everything in the SequencerService The final step is to trigger our new logic from the main game beat. In the SequencerService: Go to the update method where you deleted the old showStep calls. In their place, add a single, clean line of code: uiService.updateColumnHighlight(this.currentStep).

User prompt

Create the Main Highlighting Logic in UIService This is where we'll implement the core visual rule. In the UIService: Create a new method called updateColumnHighlight. It should accept one argument: the currentColumnIndex. Inside this new method, here's the logic: First, loop through your columnHighlights and hide them all (alpha = 0). This clears the highlight from the previous beat and ensures we start fresh. Next, call the new helper method you just made: gridService.getActiveStatesForColumn(currentColumnIndex) to get the array of active states for the current column. Now, loop from i = 0 to GameConstants.BEAT_ROWS - 1. This loop goes through each highlight object and its corresponding cell state. Here is the key rule: Inside the loop, check if the cell for that row is inactive (activeStates[i] is false). If it is inactive, you've found a cell that needs to be highlighted! Take the corresponding highlight object from your columnHighlights array (this.columnHighlights[i]). Position it correctly. Its X coordinate will be based on the currentColumnIndex, and its Y coordinate will be based on the beat grid row i. You can copy the positioning math from where the BeatCells are created in GridService. Finally, make cellWhite visible by setting its alpha to your desired highlight level (e.g., 0.2).

User prompt

In the GridService: Create a new method called getActiveStatesForColumn. This method should accept one argument: a columnIndex. Inside the method, create an array of booleans that represents the active state of each BeatCell in that column. For example, it would return [grid[0][columnIndex].active, grid[1][columnIndex].active, grid[2][columnIndex].active]. use cellWhite for this

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create a new asset named cellWhite and make it white. In the UIService: Add a new property to hold our highlight objects, maybe called columnHighlights = []. In the initialize method, create a loop that runs GameConstants.BEAT_ROWS times (so it creates one highlight for each row in the beat grid). Inside the loop, create a new 'highlight' asset. Make it semi-transparent (e.g., alpha: 0.2) so it doesn't completely block the cell background. Make sure its initial alpha is 0 so it's invisible by default. Add each new highlight object to the game and also store it in your columnHighlights array.

User prompt

In the UIService: Go to the initialize method. Find the for loop that creates the stepIndicators and adds them to the game. Delete that entire block of code. You can also delete the stepIndicators array property from the service. In the SequencerService: In the update method, you'll see calls to uiService.showStep(...) and uiService.hideOldStep(...). Delete both of those lines. Back in UIService: You can now delete the showStep and hideOldStep methods entirely, as they are no longer being called.

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Please fix the bug: 'coinService is not defined' in or related to this line: 'var sequencerService = new SequencerService(gridService, playerService, coinService, uiService);' Line Number: 605

User prompt

remove the coins logic from the game and any code related to it please

User prompt

instead of showing a moving block under the grid to show the beat, highlight the entire layer of that column for the beat cells, by making the empty cells on that layer have a white graphic over them. so REMOVE the current moving marker, and replace the visual indicator bu highlighting the 4 beat cells above it. if one of the layer contains a beat on any of the layer, only highlight the OTHER 3 remainign empty beat cells on that layer

User prompt

instead of showing a moving block under the grid to show the beat, highlight the entire layer of that column for the beat cells, by making the empty cells on that layer have a white graphic over them

Code edit (1 edits merged)

Please save this source code

User prompt

move the whole grid 50 pixels lower please

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remove one row from the top please

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your diagram can't be correct because i see the beat rows at the bottom! anywhay doesnt matter, ensure the character doesnt teleport from row 0 to row 11, rather from row 0 it must teleport to row 7

User prompt

centralize the grid into a single class, so both the beat tiles and the playable area where the character can move inside, are part of the same grid, just ensure you separate their functions and behaviours. if the grid is numbered from top down, the first 7 rows would be the playable area and the bottom 4 would be the beat grid where the player places beat tiles

User prompt

The character’s movement logic should ensure that after any move (up or down), if the new `gridRow` is less than 5, it should teleport to 11; if it’s greater than 11, it should teleport to 5. - This keeps the character always within the playable area.

User prompt

so counting from bottom to top, the first 4 rows are Beat Area grid, and the characetr should not be able to travel on those, and between row 5 and 11 is the palayable grid area where the character can move, so when teleporting, use the 5th row from the bottom as the lowest playable point. so counting from bottom towards top, first 4 rows are beat grid and the character cannot move there, and counting upwards still from row 5 to 11, is the playable area, so the character teleports on row 11 or 5, COUNTING FROM THE BOTTOM TOWARDS UP

/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
/** 
* BeatCell
* Responsibility: To model the state of a single cell on the beat grid. It no longer
* handles its own graphics updates directly, this is delegated to the GridService.
*/ 
var BeatCell = Container.expand(function (row) {
	var self = Container.call(this);
	self.active = false;
	self.row = row; // Know its row for external logic to interpret
	self.gfx = self.attachAsset('cell', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.toggle = function () {
		self.active = !self.active;
	};
	self.setActive = function (val) {
		if (self.active !== val) {
			self.toggle();
		}
	};
	// The `down` event is removed and is now handled by the central InputService.
	return self;
});
/** 
* Hero
* Responsibility: To model the player character. It manages its own state and animations,
* but no longer triggers its own sound effects.
*/ 
var Hero = Container.expand(function () {
	var self = Container.call(this);
	self.gfx = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Remove jumpInd and jump logic
	self.currentCol = 0;
	self.gridRow = GameConstants.CHAR_ROW;
	self.moveTo = function (nx, ny, duration) {
		tween(self, {
			x: nx,
			y: ny
		}, {
			duration: duration || 180,
			easing: tween.cubicOut
		});
	};
	return self;
});

/**** 
* Initialize Game
****/ 
/************************* 
* SERVICES
*************************/ 
/** 
* AudioService
* Responsibility: To handle all requests to play sounds and music.
*/ 
/************************* 
* INITIALIZE & RUN GAME
*************************/ 
// 1. Create Game Instance
var game = new LK.Game({
	backgroundColor: 0x181830
});

/**** 
* Game Code
****/ 
/** 
* GameGrid
* Responsibility: Centralizes the entire grid (playable + beat area) into a single class.
* Provides accessors for both the playable area and the beat grid, and manages their state.
*/ 
/************************* 
* CORE GAME OBJECTS
*************************/ 
// 2. Instantiate All Services
/************************* 
* ASSETS & PLUGINS
*************************/ 
// Assets (Unchanged)
// Plugins (Unchanged)
/************************* 
* GAME CONFIGURATION
*************************/ 
/** 
* GameConstants
* Responsibility: To hold all static configuration and magic numbers in one place
* for easy tuning and maintenance.
*/ 
function GameGrid(game) {
	this.game = game;
	this.rows = GameConstants.TOTAL_ROWS;
	this.cols = GameConstants.GRID_COLS;
	this.grid = []; // 2D array: [row][col] for all rows (playable + beat)
	this.beatRows = GameConstants.BEAT_ROWS;
	this.playableRows = this.rows - this.beatRows;
	// Initialize grid with nulls
	for (var r = 0; r < this.rows; r++) {
		this.grid[r] = [];
		for (var c = 0; c < this.cols; c++) {
			this.grid[r][c] = null;
		}
	}
	// Create background visuals for all cells
	this.initBackground = function () {
		for (var r = 0; r < this.rows; r++) {
			for (var c = 0; c < this.cols; c++) {
				var bgCell = LK.getAsset('emptycell', {
					anchorX: 0.5,
					anchorY: 0.5,
					alpha: 0.3
				});
				bgCell.x = GameConstants.GRID_LEFT + c * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				bgCell.y = GameConstants.GRID_TOP + r * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				this.game.addChild(bgCell);
			}
		}
	};
	// Create BeatCell objects for the beat grid (bottom rows)
	this.initBeatGrid = function () {
		for (var r = 0; r < this.beatRows; r++) {
			var gridRow = this.playableRows + r;
			for (var c = 0; c < this.cols; c++) {
				var cell = new BeatCell(r);
				cell.x = GameConstants.GRID_LEFT + c * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				cell.y = GameConstants.GRID_TOP + gridRow * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				this.game.addChild(cell);
				this.grid[gridRow][c] = cell;
			}
		}
	};
	// Returns the BeatCell at a given (beatRow, col) in the beat grid
	this.getBeatCell = function (beatRow, col) {
		var gridRow = this.playableRows + beatRow;
		return this.grid[gridRow][col];
	};
	// Returns the BeatCell at a given (x, y) screen coordinate, or null if not in beat grid
	this.getBeatCellAt = function (x, y) {
		for (var r = 0; r < this.beatRows; r++) {
			var gridRow = this.playableRows + r;
			for (var c = 0; c < this.cols; c++) {
				var cell = this.grid[gridRow][c];
				if (!cell) {
					continue;
				}
				var cx = GameConstants.GRID_LEFT + c * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				var cy = GameConstants.GRID_TOP + gridRow * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
				if (x >= cx - GameConstants.CELL_SIZE / 2 && x <= cx + GameConstants.CELL_SIZE / 2 && y >= cy - GameConstants.CELL_SIZE / 2 && y <= cy + GameConstants.CELL_SIZE / 2) {
					return cell;
				}
			}
		}
		return null;
	};
	// Returns true if (row, col) is in the playable area
	this.isPlayableCell = function (row, col) {
		return row >= 0 && row < this.playableRows && col >= 0 && col < this.cols;
	};
	// Returns true if (row, col) is in the beat grid
	this.isBeatCell = function (row, col) {
		return row >= this.playableRows && row < this.rows && col >= 0 && col < this.cols;
	};
	// Returns the BeatCell 2D array for the beat grid (bottom rows)
	this.getBeatGrid = function () {
		var arr = [];
		for (var r = 0; r < this.beatRows; r++) {
			arr[r] = [];
			for (var c = 0; c < this.cols; c++) {
				arr[r][c] = this.getBeatCell(r, c);
			}
		}
		return arr;
	};
	// Returns the playable area as a 2D array (nulls, or game objects if you want to add them)
	this.getPlayableGrid = function () {
		var arr = [];
		for (var r = 0; r < this.playableRows; r++) {
			arr[r] = [];
			for (var c = 0; c < this.cols; c++) {
				arr[r][c] = this.grid[r][c];
			}
		}
		return arr;
	};
	// Call this to initialize all visuals
	this.initialize = function () {
		this.initBackground();
		this.initBeatGrid();
	};
}
var GameConstants = {
	GRID_COLS: 8,
	TOTAL_ROWS: 11,
	// +1 for new down row
	BEAT_ROWS: 4,
	// +1 for new down row
	CHAR_ROW: 4,
	// hero now starts at row 4 (was 5)
	JUMP_ROW: 3,
	// up movement now at row 3 (was 4)
	DOWN_ROW: 2,
	// new down movement row
	GRID_MARGIN_X: 40,
	get CELL_SIZE() {
		return Math.floor((2048 - 2 * this.GRID_MARGIN_X) / this.GRID_COLS);
	},
	get GRID_HEIGHT() {
		return this.TOTAL_ROWS * this.CELL_SIZE;
	},
	get GRID_TOP() {
		return 2732 - this.GRID_HEIGHT - 10;
	},
	get GRID_LEFT() {
		return this.GRID_MARGIN_X;
	},
	get HERO_MIN_X() {
		return this.GRID_LEFT + this.CELL_SIZE / 2;
	},
	get HERO_MAX_X() {
		return this.GRID_LEFT + (this.GRID_COLS - 1) * this.CELL_SIZE + this.CELL_SIZE / 2;
	},
	get HERO_START_COL() {
		return Math.floor(this.GRID_COLS / 2);
	},
	get HERO_START_X() {
		return this.GRID_LEFT + this.HERO_START_COL * this.CELL_SIZE + this.CELL_SIZE / 2;
	},
	get HERO_START_Y() {
		return this.GRID_TOP + this.CHAR_ROW * this.CELL_SIZE + this.CELL_SIZE / 2;
	},
	STEP_INTERVAL: 400,
	// ms per step (150bpm)
	COIN_SPAWN_BEATS: 8,
	COIN_SPAWN_CHANCE: 0.25
};
/************************* 
* SERVICES
*************************/ 
/** 
* AudioService
* Responsibility: To handle all requests to play sounds and music.
*/ 
var AudioService = {
	playBeat: function playBeat() {
		LK.getSound('beat').play();
	},
	playJump: function playJump() {
		LK.getSound('jumpSnd').play();
	},
	playMove: function playMove() {
		LK.getSound('moveSnd').play();
	},
	startMusic: function startMusic() {
		LK.playMusic('bgmusic', {
			fade: {
				start: 0,
				end: 0.3,
				duration: 1200
			}
		});
	}
};
/** 
* UIService
* Responsibility: To create and manage all non-game-grid UI elements, such
* as the score text and the step indicators.
*/ 
function UIService(game) {
	this.game = game;
	this.scoreTxt = null;
	this.initialize = function () {
		// Score Text
		this.scoreTxt = new Text2('0', {
			size: 100,
			fill: "#fff"
		});
		this.scoreTxt.anchor.set(0.5, 0);
		LK.gui.top.addChild(this.scoreTxt);
		// Create columnHighlights for beat grid rows
		this.columnHighlights = [];
		for (var r = 0; r < GameConstants.BEAT_ROWS; r++) {
			var highlight = LK.getAsset('cellWhite', {
				anchorX: 0.5,
				anchorY: 0.5,
				alpha: 0 // invisible by default
			});
			// Position highlight at the leftmost column, correct row in the beat grid
			var gridRow = GameConstants.TOTAL_ROWS - GameConstants.BEAT_ROWS + r;
			highlight.x = GameConstants.GRID_LEFT + GameConstants.CELL_SIZE / 2;
			highlight.y = GameConstants.GRID_TOP + gridRow * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
			highlight.alpha = 0; // invisible by default, semi-transparent when shown
			this.game.addChild(highlight);
			this.columnHighlights.push(highlight);
		}
	};
	this.updateScore = function (newScore) {
		this.scoreTxt.setText(newScore);
	};
}
/** 
* GridService
* Responsibility: To create, manage the state of, and update the visuals of the beat grid.
*/ 
function GridService(game, gameGrid) {
	this.game = game;
	this.gameGrid = gameGrid; // Centralized grid
	this.initialize = function () {
		this.gameGrid.initialize();
	};
	// Returns the BeatCell at a given (x, y) screen coordinate, or null if not in beat grid
	this.getCellAt = function (x, y) {
		return this.gameGrid.getBeatCellAt(x, y);
	};
	// Toggle a beat cell, ensuring only one beat per layer per column
	this.toggleCell = function (cell, mode) {
		var needsChange = mode === 'add' && !cell.active || mode === 'remove' && cell.active;
		if (needsChange) {
			// If adding, remove any other active beat in this column (same col, different row)
			if (mode === 'add') {
				var col = null;
				// Find the column index of this cell
				for (var c = 0; c < GameConstants.GRID_COLS; c++) {
					// cell.row is the beat row (0..BEAT_ROWS-1), but grid is [playableRows+row][col]
					var gridRow = GameConstants.TOTAL_ROWS - GameConstants.BEAT_ROWS + cell.row;
					if (this.gameGrid.grid[gridRow][c] === cell) {
						col = c;
						break;
					}
				}
				if (col !== null) {
					for (var r = 0; r < GameConstants.BEAT_ROWS; r++) {
						var gridRow = GameConstants.TOTAL_ROWS - GameConstants.BEAT_ROWS + r;
						var otherCell = this.gameGrid.grid[gridRow][col];
						if (r !== cell.row && otherCell && otherCell.active) {
							otherCell.setActive(false);
							this.updateCellVisual(otherCell);
						}
					}
				}
			}
			cell.toggle();
			this.updateCellVisual(cell);
		}
	};
	this.updateCellVisual = function (cell) {
		cell.gfx.destroy();
		var assetId = 'cell';
		if (cell.active) {
			if (cell.row === 0) {
				assetId = 'cellActive';
			} else if (cell.row === 1) {
				assetId = 'cellLeft';
			} else if (cell.row === 2) {
				assetId = 'cellRight';
			} else if (cell.row === 3) {
				assetId = 'cellDown';
			}
		}
		cell.gfx = cell.attachAsset(assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
	};
	// Returns the actions for a given step (column) by checking the beat grid
	this.getActiveActionsForStep = function (step) {
		// The beat grid is in the bottom rows of the grid
		var actions = {
			up: false,
			left: false,
			right: false,
			down: false
		};
		for (var r = 0; r < GameConstants.BEAT_ROWS; r++) {
			var gridRow = GameConstants.TOTAL_ROWS - GameConstants.BEAT_ROWS + r;
			var cell = this.gameGrid.grid[gridRow][step];
			if (!cell) {
				continue;
			}
			if (r === 0) {
				actions.up = cell.active;
			} else if (r === 1) {
				actions.left = cell.active;
			} else if (r === 2) {
				actions.right = cell.active;
			} else if (r === 3) {
				actions.down = cell.active;
			}
		}
		return actions;
	};
}
/** 
* PlayerService
* Responsibility: To create and manage the Hero instance, its state, and its actions.
* It translates logical actions ("move left") into animations and sound calls.
*/ 
function PlayerService(game) {
	this.game = game;
	this.hero = null;
	this.initialize = function () {
		this.hero = new Hero();
		this.hero.x = GameConstants.HERO_START_X;
		this.hero.y = GameConstants.HERO_START_Y;
		this.hero.currentCol = GameConstants.HERO_START_COL;
		this.hero.gridRow = GameConstants.CHAR_ROW;
		this.game.addChild(this.hero);
	};
	this.getHeroInstance = function () {
		return this.hero;
	};
	this.handleDrag = function (x) {
		this.hero.x = Math.max(GameConstants.HERO_MIN_X, Math.min(GameConstants.HERO_MAX_X, x));
	};
	this.performActions = function (actions) {
		var didAction = false;
		var horizontalMove = 0;
		if (actions.left && !actions.right) {
			horizontalMove = -1;
		}
		if (actions.right && !actions.left) {
			horizontalMove = 1;
		}
		if (actions.up && !actions.down) {
			if (horizontalMove !== 0) {
				this.move(horizontalMove);
			}
			this.moveVertical(-1); // Move up
			didAction = true;
		} else if (actions.down && !actions.up) {
			if (horizontalMove !== 0) {
				this.move(horizontalMove);
			}
			this.moveVertical(1); // Move down
			didAction = true;
		} else if (horizontalMove !== 0) {
			this.move(horizontalMove);
			didAction = true;
		}
		if (didAction) {
			AudioService.playBeat();
		}
	};
	this.move = function (direction) {
		var newCol = this.hero.currentCol + direction;
		if (newCol < 0) {
			newCol = GameConstants.GRID_COLS - 1;
		}
		if (newCol >= GameConstants.GRID_COLS) {
			newCol = 0;
		}
		this.hero.currentCol = newCol;
		var nx = GameConstants.GRID_LEFT + newCol * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
		this.hero.moveTo(nx, this.hero.y, 180);
		AudioService.playMove();
	};
	// Move up or down by 1 row, with vertical teleport at edges of playable area
	this.moveVertical = function (direction) {
		var minRow = 0;
		var maxRow = gameGrid.playableRows - 1; // Only teleport within playable area (rows 0-6)
		var newRow = this.hero.gridRow !== undefined ? this.hero.gridRow : GameConstants.CHAR_ROW;
		newRow += direction;
		// Teleport vertically if out of bounds
		if (newRow < minRow) {
			newRow = maxRow;
		} else if (newRow > maxRow) {
			newRow = minRow;
		}
		this.hero.gridRow = newRow;
		var ny = GameConstants.GRID_TOP + newRow * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
		this.hero.moveTo(this.hero.x, ny, 180);
		AudioService.playMove();
		// Update CHAR_ROW for collision logic
		GameConstants.CHAR_ROW = newRow;
	};
	this.standAndJump = function () {
		// No longer used, but kept for compatibility
	};
}
/** 
* InputService
* Responsibility: To handle all raw user input (down, up, move) and delegate
* the appropriate actions to other services (GridService, PlayerService).
*/ 
function InputService(gridService, playerService) {
	this.gridService = gridService;
	this.playerService = playerService;
	this.isPainting = false;
	this.paintMode = null;
	this.lastPaintedCell = null;
	this.dragHero = false;
	this.handleDown = function (x, y) {
		var cell = this.gridService.getCellAt(x, y);
		if (cell) {
			this.isPainting = true;
			this.paintMode = cell.active ? 'remove' : 'add';
			this.lastPaintedCell = cell;
			this.gridService.toggleCell(cell, this.paintMode);
		} else {
			var hero = this.playerService.getHeroInstance();
			var dx = x - hero.x,
				dy = y - hero.y;
			if (dx * dx + dy * dy < 200 * 200) {
				this.dragHero = true;
			}
		}
	};
	this.handleUp = function () {
		this.isPainting = false;
		this.paintMode = null;
		this.lastPaintedCell = null;
		this.dragHero = false;
	};
	this.handleMove = function (x, y) {
		if (this.isPainting) {
			var cell = this.gridService.getCellAt(x, y);
			if (cell && cell !== this.lastPaintedCell) {
				this.lastPaintedCell = cell;
				this.gridService.toggleCell(cell, this.paintMode);
			}
		} else if (this.dragHero) {
			this.playerService.handleDrag(x);
		}
	};
}
/** 
* SequencerService
* Responsibility: To manage the main game loop timing (the "beat"). On each step,
* it orchestrates calls to the other services to update the game state.
*/ 
function SequencerService(gridService, playerService, uiService) {
	this.gridService = gridService;
	this.playerService = playerService;
	this.uiService = uiService;
	this.currentStep = 0;
	this.lastStepTime = 0;
	this.playing = true;
	this.initialize = function () {
		this.lastStepTime = Date.now();
	};
	this.update = function () {
		var now = Date.now();
		if (this.playing && now - this.lastStepTime >= GameConstants.STEP_INTERVAL) {
			this.lastStepTime = now;
			this.currentStep = (this.currentStep + 1) % GameConstants.GRID_COLS;
			this.doStepActions();
		}
	};
	this.doStepActions = function () {
		var actions = this.gridService.getActiveActionsForStep(this.currentStep);
		this.playerService.performActions(actions);
		var hero = this.playerService.getHeroInstance();
	};
}
var uiService = new UIService(game);
var gameGrid = new GameGrid(game);
var gridService = new GridService(game, gameGrid);
var playerService = new PlayerService(game);
var inputService = new InputService(gridService, playerService);
var sequencerService = new SequencerService(gridService, playerService, uiService);
// 3. Initialize Services in correct order
uiService.initialize();
gridService.initialize();
playerService.initialize();
sequencerService.initialize();
// 4. Connect Input Handlers to the Input Service
game.down = function (x, y) {
	inputService.handleDown(x, y);
};
game.up = function (x, y) {
	inputService.handleUp(x, y);
};
game.move = function (x, y) {
	inputService.handleMove(x, y);
};
// 5. Set Main Game Loop to the Sequencer Service
game.update = function () {
	sequencerService.update();
};
// 6. Start background music
AudioService.startMusic();

===================================================================
--- original.js
+++ change.js
@@ -287,8 +287,24 @@
 			fill: "#fff"
 		});
 		this.scoreTxt.anchor.set(0.5, 0);
 		LK.gui.top.addChild(this.scoreTxt);
+		// Create columnHighlights for beat grid rows
+		this.columnHighlights = [];
+		for (var r = 0; r < GameConstants.BEAT_ROWS; r++) {
+			var highlight = LK.getAsset('cellWhite', {
+				anchorX: 0.5,
+				anchorY: 0.5,
+				alpha: 0 // invisible by default
+			});
+			// Position highlight at the leftmost column, correct row in the beat grid
+			var gridRow = GameConstants.TOTAL_ROWS - GameConstants.BEAT_ROWS + r;
+			highlight.x = GameConstants.GRID_LEFT + GameConstants.CELL_SIZE / 2;
+			highlight.y = GameConstants.GRID_TOP + gridRow * GameConstants.CELL_SIZE + GameConstants.CELL_SIZE / 2;
+			highlight.alpha = 0; // invisible by default, semi-transparent when shown
+			this.game.addChild(highlight);
+			this.columnHighlights.push(highlight);
+		}
 	};
 	this.updateScore = function (newScore) {
 		this.scoreTxt.setText(newScore);
 	};