Thanks a lot for the feedback! I'm really glad you enjoyed the game :)
About the upgrade system: basically, when you hover over the icon for the upgrade type (health, weapon upgrade, speed, etc.), it shows the items needed to level up that skill. The planets work the same way (unfortunately, We didn’t have time to implement visual feedback for the upgrades).
About the lag when breaking asteroids, that's actually a hitstop mechanic designed to emphasize the impact, but I can see how it might have been a bit confusing in this context