Hey, I appreciate the feedback! I'm thinking of making the waves longer overall so the players actually have enough balance to spend and it never feels like an interruption. I'll probably end up re balancing the prices/upgrades as well to fit the new wave length.
I agree that the HUD should provide more info, I'm still trying to find a way to fit the icons on screen because enemies spawn unconventionally at the top of the viewport, which is where most games would usually place their icons and game info. Still working on that point.
Finally thanks for pointing out the bug that Itch.io is hiding the buttons, I'll be sure to fix that for the next update!