This is really great for your first game!
I didn't encounter any bugs, and all the weapons you are given feel unique in their use.
One thing, though, the difficulty scales extremely fast. At first, you're dealing with say 4 to 5 zombies, and then 10 seconds later, you are completely dogpiled by a horde of zombies.
Mostly just a balancing issue, the game and the weapons work well!