var ToxicFly = Container.expand(function () {
	var self = Container.call(this);
	var toxicFlyGraphics = self.createAsset('toxicFly', 'Toxic Fly', .5, .5);
	toxicFlyGraphics.scale.set(1);
	self.move = function () {
		self.x += self.vx;
		self.y += self.vy;
	};
});
var Frog = Container.expand(function () {
	var self = Container.call(this);
	self.vx = 0;
	self.vy = 0;
	self.gravity = 0.5;
	var frogGraphics = self.createAsset('frog', 'Frog character', .5, .5);
	frogGraphics.scale.set(2);
	self.jump = function (targetX, targetY) {
		var dx = targetX - self.x;
		var dy = targetY - self.y;
		var angle = Math.atan2(dy, dx);
		self.vx = Math.cos(angle) * 20;
		self.vy = Math.sin(angle) * 20;
	};
	self.dodge = function (targetX, targetY) {
		var dx = targetX - self.x;
		var dy = targetY - self.y;
		var angle = Math.atan2(dy, dx);
		self.vx = Math.cos(angle) * 10;
		self.vy = Math.sin(angle) * 10;
	};
});
var LilyPad = Container.expand(function () {
	var self = Container.call(this);
	var lilyPadGraphics = self.createAsset('lilyPad', 'Lily pad', .5, .5);
	lilyPadGraphics.scale.set(3, 1);
	self.move = function () {};
	self.checkCollision = function (otherLilyPad) {
		var dx = self.x - otherLilyPad.x;
		var dy = self.y - otherLilyPad.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		return distance < self.width / 2 + otherLilyPad.width / 2;
	};
});
var Danger = Container.expand(function () {
	var self = Container.call(this);
	var dangerGraphics = self.createAsset('danger', 'Danger', .5, .5);
	self.move = function () {};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var background = self.createAsset('background', 'Game Background', 0, 0);
	background.width = 2048;
	background.height = 2732;
	var frog = self.addChild(new Frog());
	var lilyPads = [];
	for (var i = 0; i < 5; i++) {
		var lilyPad = new LilyPad();
		do {
			lilyPad.x = Math.random() * 2048;
			lilyPad.y = Math.random() * 2732 / 2 + 2732 / 2;
		} while (lilyPads.some(function (otherLilyPad) {
			return lilyPad.checkCollision(otherLilyPad);
		}));
		lilyPads.push(lilyPad);
		self.addChild(lilyPad);
	}
	var dangers = [];
	var toxicFlies = [];
	frog.x = 2048 / 2;
	frog.y = 2732 / 2;
	var spawnToxicFly = function () {
		var toxicFly = new ToxicFly();
		toxicFly.x = Math.random() * 2048;
		toxicFly.y = Math.random() * 2732;
		var dx = frog.x - toxicFly.x;
		var dy = frog.y - toxicFly.y;
		var angle = Math.atan2(dy, dx);
		toxicFly.vx = Math.cos(angle) * 15;
		toxicFly.vy = Math.sin(angle) * 15;
		toxicFlies.push(toxicFly);
		self.addChild(toxicFly);
	};
	LK.setInterval(spawnToxicFly, 3000);
	LK.on('tick', function () {
		frog.x += frog.vx;
		frog.y += frog.vy;
		frog.vy += frog.gravity;
		for (var i = 0; i < lilyPads.length; i++) {
			if (frog.intersects(lilyPads[i])) {
				frog.vy = -10;
			}
		}
		for (var i = 0; i < toxicFlies.length; i++) {
			if (frog.intersects(toxicFlies[i])) {
				LK.showGameOver();
			}
		}
		for (var i = 0; i < lilyPads.length; i++) {
			lilyPads[i].move();
			if (lilyPads[i].x < -50) {
				lilyPads[i].destroy();
				lilyPads.splice(i, 1);
			}
		}
		for (var i = 0; i < toxicFlies.length; i++) {
			toxicFlies[i].move(frog.x, frog.y);
			if (toxicFlies[i].x < -50 || toxicFlies[i].x > 2048 || toxicFlies[i].y < -50 || toxicFlies[i].y > 2732) {
				toxicFlies[i].destroy();
				toxicFlies.splice(i, 1);
			}
		}
	});
	stage.on('down', function (obj) {
		var event = obj.event;
		var pos = event.getLocalPosition(self);
		frog.jump(pos.x, pos.y);
	});
});

===================================================================
--- original.js
+++ change.js
@@ -1,14 +1,9 @@
 var ToxicFly = Container.expand(function () {
 	var self = Container.call(this);
 	var toxicFlyGraphics = self.createAsset('toxicFly', 'Toxic Fly', .5, .5);
 	toxicFlyGraphics.scale.set(1);
-	self.move = function (targetX, targetY) {
-		var dx = targetX - self.x;
-		var dy = targetY - self.y;
-		var angle = Math.atan2(dy, dx) + (Math.random() > 0.5 ? -1 : 1) * Math.PI / 6;
-		self.vx = Math.cos(angle) * 15;
-		self.vy = Math.sin(angle) * 15;
+	self.move = function () {
 		self.x += self.vx;
 		self.y += self.vy;
 	};
 });
@@ -76,8 +71,13 @@
 	var spawnToxicFly = function () {
 		var toxicFly = new ToxicFly();
 		toxicFly.x = Math.random() * 2048;
 		toxicFly.y = Math.random() * 2732;
+		var dx = frog.x - toxicFly.x;
+		var dy = frog.y - toxicFly.y;
+		var angle = Math.atan2(dy, dx);
+		toxicFly.vx = Math.cos(angle) * 15;
+		toxicFly.vy = Math.sin(angle) * 15;
 		toxicFlies.push(toxicFly);
 		self.addChild(toxicFly);
 	};
 	LK.setInterval(spawnToxicFly, 3000);