I admit I was never a big fan of clicker games, but I can definitely see why you chose to use this game for trying out Godot. It's fairly simple gameplay wise, but it does have some nice little sounds for clicking at the right or wrong time, and can get pretty challenging once you hit max speed.
I never got any higher than 40 so I didn't see the surprise whatever it was. And I did find there were a couple times that it seemed like my click should have registered as correct but didn't. I don't know if there was a specific part of the circles I'm supposed to click on or if they need to be clicked exactly when the ring overlaps with the white rim of the ball.
The music was kinda fun but imo became annoying after a little bit.