===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,444 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
+* Classes
+****/ 
+// UnicornCell: Represents a single cell in the Sudoku grid
+var UnicornCell = Container.expand(function () {
+	var self = Container.call(this);
+	// Cell background (for selection/highlight)
+	var bg = self.attachAsset('cellBg', {
+		width: cellSize - 8,
+		height: cellSize - 8,
+		color: 0xffffff,
+		shape: 'box',
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.bg = bg;
+	// The unicorn icon (if any)
+	self.icon = null;
+	self.unicornIndex = null; // 0-8, or null if empty
+	// Row, col for logic
+	self.row = 0;
+	self.col = 0;
+	// Is this a given (pre-filled) cell?
+	self.isGiven = false;
+	// Show error highlight
+	self.showError = function (on) {
+		if (on) {
+			tween(self.bg, {
+				color: 0xffaaaa
+			}, {
+				duration: 200,
+				easing: tween.easeIn
+			});
+		} else {
+			tween(self.bg, {
+				color: 0xffffff
+			}, {
+				duration: 200,
+				easing: tween.easeOut
+			});
+		}
+	};
+	// Set unicorn icon
+	self.setUnicorn = function (idx, animate) {
+		if (self.icon) {
+			self.removeChild(self.icon);
+			self.icon = null;
+		}
+		self.unicornIndex = idx;
+		if (idx !== null) {
+			var icon = self.attachAsset('unicorn' + idx, {
+				width: cellSize * 0.7,
+				height: cellSize * 0.7,
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.icon = icon;
+			if (animate) {
+				icon.scaleX = 0.2;
+				icon.scaleY = 0.2;
+				tween(icon, {
+					scaleX: 1,
+					scaleY: 1
+				}, {
+					duration: 180,
+					easing: tween.bounceOut
+				});
+			}
+		}
+	};
+	// Remove unicorn icon
+	self.clearUnicorn = function () {
+		if (self.icon) {
+			self.removeChild(self.icon);
+			self.icon = null;
+		}
+		self.unicornIndex = null;
+	};
+	// Selection highlight
+	self.setSelected = function (on) {
+		if (on) {
+			tween(self.bg, {
+				color: 0xcce6ff
+			}, {
+				duration: 120
+			});
+		} else {
+			tween(self.bg, {
+				color: 0xffffff
+			}, {
+				duration: 120
+			});
+		}
+	};
+	return self;
+});
+// UnicornPicker: The row of unicorn icons for selection
+var UnicornPicker = Container.expand(function () {
+	var self = Container.call(this);
+	self.icons = [];
+	self.visible = false;
+	self.selectedIdx = null;
+	// Create 9 unicorn icons
+	for (var i = 0; i < 9; i++) {
+		var icon = self.attachAsset('unicorn' + i, {
+			width: pickerIconSize,
+			height: pickerIconSize,
+			anchorX: 0.5,
+			anchorY: 0.5,
+			x: i * (pickerIconSize + pickerGap),
+			y: 0
+		});
+		icon.idx = i;
+		self.icons.push(icon);
+	}
+	// Background
+	var pickerBg = self.attachAsset('pickerBg', {
+		width: 9 * pickerIconSize + 8 * pickerGap + 32,
+		height: pickerIconSize + 32,
+		color: 0xf7e6ff,
+		shape: 'box',
+		anchorX: 0,
+		anchorY: 0
+	});
+	pickerBg.x = -16;
+	pickerBg.y = -16;
+	self.setChildIndex(pickerBg, 0);
+	// Highlight selected
+	self.setSelected = function (idx) {
+		for (var i = 0; i < self.icons.length; i++) {
+			self.icons[i].alpha = i === idx ? 1 : 0.7;
+			self.icons[i].scaleX = self.icons[i].scaleY = i === idx ? 1.15 : 1;
+		}
+		self.selectedIdx = idx;
+	};
+	// Show/hide
+	self.show = function (x, y) {
+		self.x = x;
+		self.y = y;
+		self.visible = true;
+	};
+	self.hide = function () {
+		self.visible = false;
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
+/**** 
+* Game Constants
+****/ 
+// Board layout
+// --- Game Initialization ---
 var game = new LK.Game({
-	backgroundColor: 0x000000
-});
\ No newline at end of file
+	backgroundColor: 0xf7e6ff
+});
+
+/**** 
+* Game Code
+****/ 
+// Board layout
+/**** 
+* Game Constants
+****/ 
+// --- Game State ---
+var gridSize = 9;
+var cellSize = 180; // 9*180 = 1620, fits well in 2048 width
+var boardSize = cellSize * gridSize;
+var boardOffsetX = (2048 - boardSize) / 2;
+var boardOffsetY = 220;
+// Picker
+var pickerIconSize = 120;
+var pickerGap = 18;
+// For error highlight
+var errorFlashDuration = 400;
+// --- Asset Initialization ---
+// 9 unicorn icons
+for (var i = 0; i < 9; i++) {}
+// Cell background
+// Picker background
+var board = []; // 2D array of UnicornCell
+var givenBoard = []; // 2D array of unicorn indices (0-8) or null
+var solutionBoard = []; // 2D array of unicorn indices (0-8)
+var selectedCell = null;
+var picker = null;
+var timerTxt = null;
+var startTime = null;
+var timerInterval = null;
+var errorCells = [];
+var completed = false;
+// --- Sudoku Puzzle Generation ---
+// For MVP, use a static puzzle and solution (easy level)
+var staticPuzzle = [[null, null, 2, null, 3, null, 7, null, null], [6, null, null, 1, 9, 5, null, null, null], [null, 9, 8, null, null, null, null, 6, null], [8, null, null, null, 6, null, null, null, 3], [4, null, null, 8, null, 3, null, null, 1], [7, null, null, null, 2, null, null, null, 6], [null, 6, null, null, null, null, 2, 8, null], [null, null, null, 4, 1, 9, null, null, 5], [null, null, 5, null, 8, null, null, 7, 9]];
+// Solution for the above puzzle (0-8 for unicorn indices)
+var staticSolution = [[0, 1, 2, 6, 3, 8, 7, 5, 4], [6, 7, 4, 1, 9, 5, 8, 2, 3], [5, 9, 8, 7, 4, 2, 1, 6, 0], [8, 5, 1, 2, 6, 7, 4, 0, 3], [4, 2, 6, 8, 5, 3, 9, 7, 1], [7, 3, 9, 5, 2, 4, 0, 8, 6], [1, 6, 3, 9, 7, 0, 5, 4, 2], [2, 8, 7, 4, 1, 9, 6, 3, 5], [9, 4, 5, 3, 8, 6, 2, 1, 7]];
+// --- Helper Functions ---
+// Returns true if placing unicornIdx at (row, col) is valid
+function isValidMove(row, col, unicornIdx) {
+	// Check row
+	for (var c = 0; c < gridSize; c++) {
+		if (c !== col && board[row][c].unicornIndex === unicornIdx) return false;
+	}
+	// Check col
+	for (var r = 0; r < gridSize; r++) {
+		if (r !== row && board[r][col].unicornIndex === unicornIdx) return false;
+	}
+	// Check 3x3 box
+	var boxRow = Math.floor(row / 3) * 3;
+	var boxCol = Math.floor(col / 3) * 3;
+	for (var r = boxRow; r < boxRow + 3; r++) {
+		for (var c = boxCol; c < boxCol + 3; c++) {
+			if ((r !== row || c !== col) && board[r][c].unicornIndex === unicornIdx) return false;
+		}
+	}
+	return true;
+}
+// Returns true if the board is completely and correctly filled
+function isBoardComplete() {
+	for (var r = 0; r < gridSize; r++) {
+		for (var c = 0; c < gridSize; c++) {
+			var cell = board[r][c];
+			if (cell.unicornIndex === null) return false;
+			if (!isValidMove(r, c, cell.unicornIndex)) return false;
+		}
+	}
+	return true;
+}
+// Highlight errors for current board state
+function highlightErrors() {
+	// Clear previous
+	for (var i = 0; i < errorCells.length; i++) {
+		errorCells[i].showError(false);
+	}
+	errorCells = [];
+	// Check for errors
+	for (var r = 0; r < gridSize; r++) {
+		for (var c = 0; c < gridSize; c++) {
+			var cell = board[r][c];
+			if (cell.unicornIndex === null) continue;
+			// Only highlight if not a given
+			if (!cell.isGiven && !isValidMove(r, c, cell.unicornIndex)) {
+				cell.showError(true);
+				errorCells.push(cell);
+			}
+		}
+	}
+}
+// Deselect all cells
+function deselectAllCells() {
+	for (var r = 0; r < gridSize; r++) {
+		for (var c = 0; c < gridSize; c++) {
+			board[r][c].setSelected(false);
+		}
+	}
+	selectedCell = null;
+}
+// --- UI Setup ---
+// Board container
+var boardContainer = new Container();
+boardContainer.x = boardOffsetX;
+boardContainer.y = boardOffsetY;
+game.addChild(boardContainer);
+// Draw grid lines (thick for boxes, thin for cells)
+for (var i = 0; i <= gridSize; i++) {
+	// Vertical
+	var lineW = i % 3 === 0 ? 8 : 3;
+	var lineColor = i % 3 === 0 ? 0x9b59b6 : 0xd1b3e0;
+	var vLine = LK.getAsset('vLine' + i, {
+		width: lineW,
+		height: boardSize,
+		color: lineColor,
+		shape: 'box',
+		anchorX: 0.5,
+		anchorY: 0
+	});
+	vLine.x = i * cellSize;
+	vLine.y = 0;
+	boardContainer.addChild(vLine);
+	// Horizontal
+	var hLine = LK.getAsset('hLine' + i, {
+		width: boardSize,
+		height: lineW,
+		color: lineColor,
+		shape: 'box',
+		anchorX: 0,
+		anchorY: 0.5
+	});
+	hLine.x = 0;
+	hLine.y = i * cellSize;
+	boardContainer.addChild(hLine);
+}
+// Create cells
+for (var r = 0; r < gridSize; r++) {
+	board[r] = [];
+	for (var c = 0; c < gridSize; c++) {
+		var cell = new UnicornCell();
+		cell.x = c * cellSize + cellSize / 2;
+		cell.y = r * cellSize + cellSize / 2;
+		cell.row = r;
+		cell.col = c;
+		boardContainer.addChild(cell);
+		board[r][c] = cell;
+	}
+}
+// Fill in given cells and solution
+for (var r = 0; r < gridSize; r++) {
+	givenBoard[r] = [];
+	solutionBoard[r] = [];
+	for (var c = 0; c < gridSize; c++) {
+		var idx = staticPuzzle[r][c];
+		var cell = board[r][c];
+		if (idx !== null) {
+			cell.setUnicorn(idx, false);
+			cell.isGiven = true;
+			cell.bg.alpha = 0.7;
+		}
+		givenBoard[r][c] = idx;
+		solutionBoard[r][c] = staticSolution[r][c];
+	}
+}
+// --- Picker UI ---
+picker = new UnicornPicker();
+picker.visible = false;
+game.addChild(picker);
+// --- Timer UI ---
+timerTxt = new Text2('00:00', {
+	size: 90,
+	fill: 0x7D3C98
+});
+timerTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(timerTxt);
+// --- Title UI ---
+var titleTxt = new Text2('Unicorn Sudoku', {
+	size: 110,
+	fill: 0xA569BD
+});
+titleTxt.anchor.set(0.5, 0);
+titleTxt.y = 10;
+LK.gui.top.addChild(titleTxt);
+// --- Instructions UI ---
+var instrTxt = new Text2('Tap a cell, then pick a unicorn to fill it!', {
+	size: 60,
+	fill: 0x7D3C98
+});
+instrTxt.anchor.set(0.5, 0);
+instrTxt.y = 120;
+LK.gui.top.addChild(instrTxt);
+// --- Event Handlers ---
+// Cell tap: select cell and show picker
+function onCellDown(x, y, obj) {
+	if (completed) return;
+	var cell = obj;
+	if (cell.isGiven) return;
+	deselectAllCells();
+	cell.setSelected(true);
+	selectedCell = cell;
+	// Show picker below the cell, but keep inside screen
+	var global = boardContainer.toGlobal(cell.position);
+	var pickerX = Math.max(40, Math.min(global.x - pickerIconSize * 4, 2048 - pickerIconSize * 9 - 40));
+	var pickerY = Math.min(global.y + cellSize / 2 + 30, 2732 - pickerIconSize - 80);
+	picker.show(pickerX, pickerY);
+	picker.setSelected(null);
+}
+// Picker tap: set unicorn in selected cell
+function onPickerDown(x, y, obj) {
+	if (!selectedCell || completed) return;
+	var idx = obj.idx;
+	if (idx === undefined) return;
+	// If already has this unicorn, clear
+	if (selectedCell.unicornIndex === idx) {
+		selectedCell.clearUnicorn();
+		picker.setSelected(null);
+	} else {
+		selectedCell.setUnicorn(idx, true);
+		picker.setSelected(idx);
+	}
+	highlightErrors();
+	// Check for win
+	if (isBoardComplete()) {
+		completed = true;
+		picker.hide();
+		deselectAllCells();
+		LK.effects.flashScreen(0x7d3c98, 800);
+		LK.setTimeout(function () {
+			LK.showYouWin();
+		}, 900);
+	}
+}
+// Hide picker if tap outside
+function onGameDown(x, y, obj) {
+	// If tap is not on a cell or picker, hide picker and deselect
+	if (obj && (obj instanceof UnicornCell || obj === picker || picker.icons.indexOf(obj) !== -1)) return;
+	picker.hide();
+	deselectAllCells();
+}
+// --- Attach event handlers ---
+// Attach to each cell
+for (var r = 0; r < gridSize; r++) {
+	for (var c = 0; c < gridSize; c++) {
+		var cell = board[r][c];
+		cell.down = onCellDown;
+	}
+}
+// Attach to picker icons
+for (var i = 0; i < picker.icons.length; i++) {
+	picker.icons[i].down = onPickerDown;
+}
+// Attach to game for outside tap
+game.down = onGameDown;
+// --- Timer Logic ---
+function formatTime(secs) {
+	var m = Math.floor(secs / 60);
+	var s = secs % 60;
+	return (m < 10 ? '0' : '') + m + ':' + (s < 10 ? '0' : '') + s;
+}
+function updateTimer() {
+	if (completed) return;
+	var now = Date.now();
+	var elapsed = Math.floor((now - startTime) / 1000);
+	timerTxt.setText(formatTime(elapsed));
+}
+// --- Game Start ---
+function startGame() {
+	completed = false;
+	deselectAllCells();
+	picker.hide();
+	highlightErrors();
+	startTime = Date.now();
+	timerTxt.setText('00:00');
+	if (timerInterval) LK.clearInterval(timerInterval);
+	timerInterval = LK.setInterval(updateTimer, 1000);
+}
+startGame();
+// --- Game Update (not used for logic, but required) ---
+game.update = function () {
+	// No per-frame logic needed for MVP
+};
\ No newline at end of file