Ok, the name didn't lie, it's literally TOO MANY BULLETS, after all XD
Although you said the audio is pre-existed, the choice is great for this game, fits your art well. And yeah, the art itself is so interesting and unusual. To be honest, some parts of the main menu were hard for reading (I guess because colors blend together), but the overall look is nice and pleasing.
Surprisingly, with all the simplicity of the game, it was so intense and satisfying, I really was on the edge of my seat all the time :D I didn't really get what is happening to the character once the bullet run out, does it stop moving forever ahaha? But apart from that, had a lot of fun! Keep up making games, I want MORE BULLETS (and games)