===================================================================
--- original.js
+++ change.js
@@ -1,11 +1,14 @@
 var Hero = Container.expand(function () {
 	var self = Container.call(this);
 	var heroGraphics = self.createAsset('hero', 'Hero character', .5, .5);
 	self.speed = 5;
-	self.move = function (x, y) {
-		self.x += x * self.speed;
-		self.y += y * self.speed;
+	self.move = function (touchStart, touchEnd) {
+		var dx = touchEnd.x - touchStart.x;
+		var dy = touchEnd.y - touchStart.y;
+		var distance = Math.sqrt(dx * dx + dy * dy);
+		self.x += dx / distance * self.speed;
+		self.y += dy / distance * self.speed;
 	};
 });
 var Enemy = Container.expand(function () {
 	var self = Container.call(this);
@@ -44,12 +47,9 @@
 		touchStart = obj.event.getLocalPosition(self);
 	});
 	stage.on('up', function (obj) {
 		touchEnd = obj.event.getLocalPosition(self);
-		var dx = touchEnd.x - touchStart.x;
-		var dy = touchEnd.y - touchStart.y;
-		var distance = Math.sqrt(dx * dx + dy * dy);
-		hero.move(dx / distance, dy / distance);
+		hero.move(touchStart, touchEnd);
 	});
 	LK.on('tick', function () {
 		for (var i = 0; i < enemies.length; i++) {
 			enemies[i].chase(hero);