Here's a review:
-LOVE the tattoo on the protag's arm.
-Could use a little improvement with the green zombie sprite. It's hard to distinguish him from the background.
-I don't understand the strafing mechanics; right clicked and the protag went slower. I think SHIFT would be a better option instead of right click as that's what's being used in most games.
-It does this weird thing where the protag doesn't immediately point the gun to the crosshair but waits until the crosshair is already in his line of sight. So it's hard to set up sneak attacks from a corner before getting into position like you'd normally do in Hotline Miami
-Lastly, while the maze structure might be good for certain uses, it makes it very easy to defeat the boss because the boss only has one projectile attack that goes straight. I found a spot in the lower right where his projectiles can't hit you but yours can. Heck I don't think the boss attacked me at all.
Hope this was helpful. Thanks.