A very nice proof-of-concept and an interesting twist on the Hotline Miami formula to combine it with zombie horde modes! The general core gameplay felt very good, shooting up and punching zombies was satisfying and it was cool to see the difficulty ramp up bit-by-bit (though maybe it ramped up too slowly as I didn't get to the behemoth without feeling like I had already seen everything beforehand). Would love to see this game fully fleshed out with bigger environments, more enemies and more weapons to give a real sense of progression and a goal to go for as it has a real good core to work off of!
There were some glitches that were annoying though. Reloading single shot guns like the shotgun and magnum allowed you to keep reloading past full and waste ammo. Doors were annoying to open/close at times, and pointless: surely doors should be a way to impede zombies by using them as barricades by tactically closing them or knock over zombies by opening them ala Hotline Miami? Maybe allow windows to be blocked as well like other horde mode games?