Nevermind, I picked up the copy from Asimov and it also locked up on the gs.
Here's a quick and dirty patched version that gets me past the lock up and seems to start the game. Please test this out and see if you have any problems. If so, let me know and I'll take a look.
http://204.16.8.40/o..._gs_patched.dsk
I've done a few IIgs "fixes" lately, and this one was a little different. The original programmer used an undocumented entry point in the Apple II ROM to read values from the paddle/joystick registers. I didn't check why, maybe to generate random values for a seed, would be my guess (I don't think the game uses a joystick).
Anyway, the problem is that because it's an undocumented entry point, the IIgs ROM has different code in the same place, and when this code is encountered it takes the program execution off the rails and into a loop. Apple preserved the documented entry points in the IIgs ROM to maintain compatibility, but the undocumented ones were open to be different and can cause unexpected results (as we see here).
If there does seem to be a problem, there's a cleaner way to fix this. In my patch, I simply bypassed the jumps into the ROM so the IIgs doesn't get looped. The code didn't look to be critical, so it should be ok. If I am wrong, there's a cleaner way to fix it that will work, but it's also more time consuming. Basically, I can copy the code from the Apple II ROM, find a small place to insert it in memory and then have the game code jump to it instead of the ROM entry point. This would create the same results as on an Apple II, without getting looped in the ROM on a IIgs.
Rich