I love the BunGun 9000! The gameplay is smooth and the upgrades are more noticable than other games. I think the animation could use a bit of work, and it's also kind of odd how the zombies don't turn around when chasing you.
The zombies feel a bit fast for zombies, and they feel a bit floaty, but that's just me. I think a better indication of their location (like an arrow pointing to currently alive zombies) and a timer for when they will next spawn would be nice.
The dine-in feels a bit too open, maybe some tables in the way to break up the open space would be nice.
All around, 4/5. Loved it!