When was Gunstar Heroes ever released on the iDevice? This is news to me. I don't see it in the app store. EDIT: Nevermind, I'm slow. I just read about it on the front page ...
I know...Although I remember leaving it paused once overnight and continuing in the morning, only to fail 20 minutes later!! Anyway as the the op, it seems to be fine in Sonic 2 at least.