My impressions: visuals are good, but gameplay is ridicuously unfair and punishing, especially for a jam game. Haven't complete the game because of that, rage quit.
Main problems: hitboxes are just wrong, there's no damage indication like blood or sound or particles or whatever, there are no checkpoints. So what it essentially means is that you are dead in the middle of the level for no visible reason, and have to deal with all these issues again and again.
The tutorial is really annoying. These messages don't remember if you saw them, block your way, don't act as a checkpoint, and they also make you release and press the movement button again.
I've spend all the ammo long before it was needed for the tutorials, and melee just didn't work (because zombies have surprising attach range which is bigger than yours and bigger than their animation, and their being hit animation is almost unnoticeable and not really different from their attack animation, so it's not possible to see if you are hitting them)
Sawblades also attack you from a range which is not believable, you are just standing on the platform nearby and you are just suddenly dead for no reason.
Jumping is hard since character has too big inertia. While you jump slowly, the platform just goes away from you, and you aren't able to compensate because air control is also very weak.
Minor things:
Somehow I've managed to crash the game while alt-tabbing and clicking, don't know exact steps to reproduce.
Some tile edges are rendered with glitchy borders
