Bugfix:

 * remove unused aliens
 * right first level

js/spaceinvaders-core.js

@@ -35,14 +35,15 @@ Game = {
 				offset = 0;
 
 			for (col = 0; col < aliens_row.length; col = col + 1) {
-				alien_width_avg = alien_width_avg + aliens_row[col].animation.width;
+				var current_width = typeof aliens_row[col] !== "undefined" ? aliens_row[col].animation.width : ALIENS_TYPE[2].width
+				alien_width_avg = alien_width_avg + current_width;
 			}
 
 			alien_width_avg = alien_width_avg / aliens_row.length;
 			offset = (PLAYGROUND_WIDTH - (aliens_row.length  * 1.5 - 0.5) * alien_width_avg) / 2;
 
 			for (col = 0; col < aliens_row.length; col = col + 1) {
-				Game.setAlien(col, row, col * wave.length + row, offset, aliens_row[col], Game.wave.move);
+				Game.setAlien(col, row, offset, aliens_row[col], Game.wave.move);
 			}
 		}
 
@@ -107,16 +108,17 @@ Game = {
 		}
 	},
 	
-	setAlien : function(x, y, id, offset, type, move) {
+	setAlien : function(x, y, offset, type, move) {
 		"use strict";
-		if( typeof type == "undefined" ) {
+		if( typeof type === "undefined" ) {
 			return;
 		}
-		var alien = new Alien("alien" + id, {
-			x : offset + x * type.animation.width * 1.5,
-			y : START_Y + (y * 1.25 * type.animation.height)
-		}, move.move, type);
-		var directions = move.init( alien.x, alien.y );
+		var id = Game.aliens.length + 1, 
+			alien = new Alien("alien" + id, {
+				x : offset + x * type.animation.width * 1.5,
+				y : START_Y + (y * 1.25 * type.animation.height)
+			}, move.move, type),
+			directions = move.init( alien.x, alien.y );
 		alien.directionX = directions.directionX;
 		alien.directionY = directions.directionY;
 		$("#actors").addSprite("alien" + id, $.extend({posx : alien.x, posy : alien.y}, alien.animation));

js/spaceinvaders-ui.js

@@ -126,10 +126,10 @@ $(function(){
 				posy: PLAYGROUND_HEIGHT - HUD_HEIGHT - 50
 			})
 			.end()
-			.addSprite("alienA", $.extend({posx : 50, posy : 300}, ALIENS[0]))
+/*			.addSprite("alienA", $.extend({posx : 50, posy : 300}, ALIENS[0]))
 			.addSprite("alienB", $.extend({posx : 50, posy : 400}, ALIENS[1]))
 			.addSprite("alienC", $.extend({posx : 50, posy : 500}, ALIENS[2]))
-			.addSprite("explosion", {
+*/			.addSprite("explosion", {
 				width: 64,
 				height: 64,
 				posx: 100,