A hotkey for "retry" would be nice. Often I think I'm close to a solution, and try to inch towards the perfect angle, but I need to move the mouse to hit retry and it's frustrating firing the same shot four times in a row... even when I wasn't on to a solution at all in the first place.
This game is dull. Not even a challenge until the timer starts going really fast, around where you should be when you get the badge. Even then the challenge is solely because the timer's fast, not because moving the rings around is organizationally difficult. I found way too much of my scoring potential to be dependent on the random number generator: you have no shot whatsoever at a perfect if it gives you six blues and yellows in a row at the wrong time.
The finishline for Infernal Drop really should be closer to the right side of the screen, not the left. I've seen so many people who completed the hop section unable to get any points because they just can't get to the finish before 2:00 runs out.
I think I would have liked this game more if the spawns were in consistent locations each round... the game's tough enough without the annoying grind behind levels that you get a bad start in.