So i ran
[daesotho@Pavel:~ ^_^]$ strace /usr/local/games/descent3/descent3 -c -g -n 2>&1 | tee strace2

Naturally, the error came at the very end.
write(2, \"\\r\\nDescent 3 Message(Error: Canno\"..., 77
Descent 3 Message(Error: Cannot find object <GuideBot>)

System Error


) = 77
exit_group(0 ...

Descent 3 says:
\"
[daesotho@Pavel:~ ^_^]$ /usr/local/games/descent3/descent3

Descent 3 Message(Error: Cannot find object <GuideBot>)

System Error
\"
and then crashes, leaving the screen in 640x480, even. xrandr -s 0...

ok. the md5sums of everything in that directory are:
[daesotho@Pavel:/usr ...