Fun game, and I can't help but think there was some form of inspiration from all of the shoot to move games from the GMTK videos. In terms of critique, finding a better or more creative way of getting information to the player is really important in games like these. Simple but charming UI goes a long way in giving a game its own feel. Generally, if a games UI looks like it could be made in a word document, it's not very good (effective yes, charming, not so much)
I also felt that limiting the bullets made the game not as enjoyable as it could have been, and well themed music always makes a game come alive.