Game would really would benefit from some sound effects. Everything also seems very small, there's a lot of empty space, could be significantly more zoomed in, this would also alleviate the bullets being tiny and barely visible.
Had trouble figuring out you need to reload, could've used a text prompt, ammo counter, sound effect, because right now it can feel like the game is bugged.
Black text on a dark background is also not a great idea, it's next to impossible to actually see what it says.