Very cool concept :) It’s a tiny bit unclear while playing what the controls are, and I believe you can stuck the UI by activating the top left machine with the robot while it’s the end of a wave on main game (I had a superposition of the minigame + the “upgrade” UI and couldn’t do a thing from here). To help fixing that, you could move the UI related to robot’s minigame below its window on the right, for instance.
It’s cool, feels like you had fun making it!!