Super cool entry, absolutely love how you guys went for a multiplayer survival game in such a short time frame.
Graphics are simple but clear enough. I had some trouble understanding that zombies were dropping bullets and not spray cans. Other than that it's pretty neat, barricads are easy to place, guns are responsive, it's a solid start to an even better game.
I had some trouble during night 2 however, where the game placed me in an endless "wait for respawn" timer despite me having a full health bar (thanks to heavy apple consumption). I think you may have a bug on that end.