Nice pixelart! I really like the character design and the 2.5D layout, I find it really cool when people nail pixel art in 3D environments , it's so pretty. Sometimes I feel like the perspective makes it a bit unclear on where the enemies' hitboxes are, but otherwise this is a really cool game with a really cool loop.
As a recomendation, I would map both the spin of the gun and the selection of the desired bullet to the right click, because you usually want to keep moving around on a survivors-like and having to stop a direction for 1 moment to change the bullet can be really tricky if you are cornered.