Interesting about the bug where the enemies don’t spawn, I did test the game as much as I could and didn’t find that, I’m really curious!
The upgrades are only available in between waves, or when you lose a live, since I wanted people to think about what they upgrade, instead of just unlocking/upgrading things whenever you have the money.
I did however not have a lot of time to balance things out, so the game is probably very unbalanced (I tried to just power up the abilities in the end so people wouldn’t be too frustrated if the game was somehow to hard, which is never fun in game jams)
Thanks for playing and leaving critical feedback !