Since I've got no more feedback, I take that for a no. All the people with R200 cards whom I heard from (including myself, I tried on two different machines) had no crashes. A little summary of what I gathered about this whole ordeal:
- The crashes only happen on MorphOS systems with R300 cards.
- They happen at completely random places. Every log I got had different backtraces, there's no clue for me to start on.
- Even if I had a system with an R300 card, I couldn't possibly debug this for the above reason.

I know many people are disappointed, feel free to blame me, but I couldn't possibly foresee this. All I can say is that if you have an R300 card, do not buy this game.