Cool entry!
I like the aesthetics, and the music choice was pretty good! I also like some of the gameplay feel things, like guns kicking you back a bit after you shoot.
For suggestions, I think the different guns could be a bit more distinct, since I didn't really understand what the difference was. Maybe you could exaggerate the sizes a bit more, or their properties? I also think you could add some more sound effects since the game can feel a bit empty without them, and it could also add some good feedback for the player!
Overall, cool entry, keep up the good work!