it feels great to play. i think making it easy to get OP and then balancing until it's hard enough is a good approach to crafting a game around a "runs and upgrades" mechanic, so you're in a good place.
hover to fire is nice. a later upgrade that works with just the direction of the cursor from the center, and lets it be any distance might be a nice QOL addition (although maybe only on/outside the circle, to prevent players from rapidly circling around the origin hmm).
Thanks for making and sharing this!