This is sort of cathartic to play, ha. The laser feels very nice to use, and the enemy variety is (initially) great. After a while, I'd have liked to see more types and tactics from the bugs.
And, as you mentioned in the description, there's definitely some balancing issues. If you upgrade the laser a couple of times, victory is essentially inevitable. And speaking of upgrades, I couldn't figure out on my first run how to do the upgrades; the purple circle thing didn't seem like a thing I could shoot, but rather a coin or something. Maybe making the things you have to shoot stuff in the scene that looks like part of the game world, rather than UI, would have helped to communicate how to use it?