Very fun game already. I made sort of a broken build with an upgraded maelstrom that goes in a circle with a magnet and a medkit attached. Plus a bloodblade (77 damage) going extremely fast (also with the same medkit) for good measure. Maybe the game could make the waves harder depending on how good you are doing. Or there could be an auto button if you make a really good build. Even on wave 50 I am ending with full health
Some issues:
* I don't know what the "lock" button in the shop does
* Interest is confusing. I didn't realize at first that it just means later waves give more money. I think it would be more intuitive if the amount listed as "reward" just went up.
* Zap seems a bit overpowered, I could go forever with just maelstrom+, booster+, and circle+