Thank you for your feedback and for giving the game a try! I'm really glad you're enjoying it so far.
You make a fair point about the downtime between upgrades. I'll definitely look into speeding up the pacing a bit — maybe by reducing the wait times or introducing upgrades more frequently. I could also add an option (like a game speed slider or a "fast mode") to let players adjust it to their liking.
Thanks again for the constructive criticism — it helps a lot!