Ah thanks a lot! That actually sounds familiar. In another port I am working on (for 68k, OS4 and WarpOS) I had exactly the same issue in the OS4 version (which also uses mplayer). Forgot about it in the meanwhile and that of course WarpOS-on-MOS-with-mplayer would also be affected.

For future games and updates I will include the -nofontconfig for WOS and OS4, thanks, I didn't know of that option actually.