Yep, it all fell apart in the last couple hours! There's a gemcrafting scene after each level, where you can add modular effects like explosions and damage types to your weapon, or buy turrets and equip them similarly. Unfortunately the wave spawning totally fell apart and we had to tape together workarounds, and you can't even end the first level! Oh well, that's game jams for you.
Thanks for playing and for your kind comments :)