Hahaha I really like this game. The concept is very original, it's a very cool mechanic to move around using the the recoil of the bullet. I noticed the different weapons have different recoils,which is a nice little detail. Your take on the theme is also pretty funny.
I did run into a bug : After dying I clicked retry, but on wave1 I killed the enemy that spawns and the game didn't progress any further. I got stuck in wave 1 and didn't see or hear any more enemies to kill. Also, I do think some auto reload when you shoot with an empty barrel would be nice to raise the pace up of the game, especially in later waves.
I really liked the artstyle of this game. The gameplay loop is quite fun and offers a lot of replayability, at least for me. Overall great game! Keep up the great work