Wow this is really one of those game jam hidden pearls! Your game is excellently paced, with a new unlock and facing new enemies at each level. You have found the absolute perfect balance between units and enemies. The game is essentially a puzzle game, about figuring out exactly which configuration you need to do, in order to beat the level.
You should really be super proud about what you've made, it is exceptionally difficult to balance a game, especially when working on it as as solo dev (which I assume you have, based on the itch page for the game). You deserve a lot more ratings and comments, as this is really a superb little gem of a game. I could easily see this being one of those classic flash games that I would spend many afternoons trying to beat as a kid. Well done making this!
Good luck with your finals, I hope it goes well! :-)
