Okay this is a super polished game and that's so impressive considering the tight turnaround. It even supports save files - wow. This taught me a lot about game design + scoping progression mechanics under time constraints. Thank you for the fun game! I managed to 100% it in 30 minutes.
One suggestion I'd have is to pump up the player damage in the final upgrades to turn them into screen-clearing, million+ damage nukes. Right now helpers quickly outscale player bonks, I'd imagine most players leave their player damage upgrades for the very end once they're maxed out on everything else, at which point there's so much on the screen it does't make any difference. Giving them that last boost would be super satisfying + probably extend the end game by a couple more minutes.