Hi
The emulator works great.
I've tested few programs and games and here are those that don't work perfectly.
First, the Fast Tracker 2:
It uses some unhandled stuff so playback mostly doesn't sound well.
This wonderful program can switch between soundblaster & GUS output on the fly,
and it has support for playing 16-bit & 8-bit samples so I'd reccomend it for testing the gus emulation.
Other problems I've noticed with it is thas GUS playback is a bit slower,
16-bit sounds are one octave up (i.e. played on the double frequency)
and if volume is at maximum, sound is sometimes distorted.
Btw., FT2 can play mod, s3m & xm modules and most common sample formats.
Impulse Tracker works well except for occasional pitch problems and
same problem with 16-bit samples.
UPDATE: Impulse tracker changes number of active channels during playback (if more than 14) and pitch of sound output then changes (probably program's "correction").
Other games that don't work with GUS emulator:
Alien Breed 2 TA : no sound
Extreme Pinbal: gives error
UFO (or X-COM 1): freezes
The Horde: freezes
Pinball Dreams2/Pinball Fantasies: Play only for a short moment.