===================================================================
--- original.js
+++ change.js
@@ -8,12 +8,12 @@
 	self.speed = 5;
 	self.shootInterval = 30;
 	self.shootTick = 0;
 	self.moveLeft = function () {
-		self.x = Math.max(self.width / 2, self.x - self.speed * 2);
+		self.x = Math.max(self.width / 2, self.x - self.speed * 4);
 	};
 	self.moveRight = function () {
-		self.x = Math.min(2048 - self.width / 2, self.x + self.speed * 2);
+		self.x = Math.min(2048 - self.width / 2, self.x + self.speed * 4);
 	};
 	self.shoot = function () {
 		if (self.shootTick <= 0) {
 			var bullet = new HeroBullet();