Also, when I tried to quit to the level select menu from inside a set, the game crashed.

I wonder if it might make for a slight improvement if there were a more eye-catching visual indicator of the player-object’s start-point. The first thing that comes to mind would be — upon starting a level for the first time, but not necessarily upon subsequent retries during that run — a slight pause while large concentric circles close in on the start position. (I’m sure I’m cribbing that idea from other games.) Things work fine as-is, but it feels slightly unfair to miss out on an Ace solely because of the time it can occasionally take to find yourself onscreen.