Great submission, I had lots of fun !
You nailed a minimalist approach of the fun of combining additive and multiplicative upgrades. That's great game design, congrats ! :D
Once you get 4-5 turrets the game gets very fun. Unfortunately at some point I got stuck in the buy menu. I could buy stuff but there wasn't a "done" button, so it's a softlock :/
Audio is very agressive and loud. The sounds don't really add up properly so they end up scratching against each other. It is pretty hard to do though.