Robot Climb: Gameplay Changes

I've finally spent some time messing with the gameplay to eliminate that horrible dead-end problem in the game where you work your way up the tower only to have taken the wrong path and must kill yourself because of it.  In order to remove this problem, I figured I might as well add the ability for the player to make blocks explode by creating a blast when you press space.  This makes the player invulnerable to being hit for a short time and blows up the blocks around him.  Also, I've changed the tiles to be stone, so that Babel (the tower) looks more like an actual tower.  There are dark blocks in the background as well, but those are purely for aesthetics.

Large: http://bit.ly/98ddHw
Small: http://bit.ly/bDqGXb