Originally Posted by Photon
My favorite, Gravity-Force, has a bug on 1.3 and later Kickstarts: After entering a high score, it Guru's. You can get past it by quickly hitting Enter (start a new game) an extra time before it has time to Guru! It also works perfectly with Kick 1.2. Apparently Stephan Wenzler uses some system variables in his track save routine.
I'm pretty sure Gravity Force is one of those daft early games that directly accesses the kickstart ROM hence why it fails on later kickstarts