I love this game. Upgrades felt impactful, the pacing was good, and collecting gems is extremely satisfying. I spent 10 minutes in the main menu collecting gems before even starting the game.
The UI can use a bit of work. Adding modules to the same spot becomes quite tedious when it starts to fill up. Being able to select multiple modules at a time would be convenient. The window to buy new modules should be bigger in my opinion. I didn't like having to scroll to buy the module I wanted over and over again.
Increasing power almost always felt better than increasing rate. I think it could use more balancing.
This is a very impressive game, especially with the time constraint. Great job! Now back to collecting gems...