Quite a hard, but nice game. Movement is fast (wich I really like). But when you are changing directions it should be faster to go to the different direction, to make it more (faster) responsive, as this game needs you to move really quickly. Also the game is hard even without the falling rocks, so maybe only when player is very high throw at him rocks.
But other than that nice game and I really like the couch using as a way to jump higher. Good job.