Pretty cool game. I've only seen like two other 3D games this jam, so that's pretty rare. Graphics and sound were quite good, though the zombie animations do feel a little stiff, especially when you kill them.
The game is quite frustrating, though. There's no reticule, so picking up the gun at the start is way harder than it has to be, same with aiming without the guns' sights. There's also nothing telling you you can use the gun's sights, so I just spent most of my first attempts whiffing shots and getting annoyed that the death screen just goes "lmao aiming good means you don't die"
The grenades also feel completely worthless since they take too long to explode. By the time they do the horde moved away from it and you just waste a grenade. Reloading also takes way too long and you just get killed immediately if you're cornered and need to reload, though I do concede that's probably intentional.
The entrances to the areas you need to unlock also aren't obvious, so I spent my first playthroughs not realizing they were there because the text that pops up was being blocked by a headphone stand I had. It's a bad idea to make progression like that not immediately clear, especially since I spent most of that time thinking I was just bad at the game. I also don't know if there's any ammo to pick up, but if there were it was easily missable as well.
There's also no feedback on taking damage, having low health, or damaging zombies, so I sometimes just died randomly and didn't understand why. I think it might've been my own grenades, but without the feedback and jumping directly to the death screen I wasn't sure.
It's overall a very solid entry, but I'd only play it again once it's a lot more polished.