The answer is, yes, it's possible. But games like Space Quest 1 VGA that someone referenced earlier in this thread, will NOT work, because they are not designed for General MIDI. Only games which separate MIDI (MU50)for music and digital sound (Sound Blaster) for SFX will work. In Sierra-land, Quest for Glory 4 would be an example. Basically, any natively General MIDI supported game *should* work, some early GM games may not, but a vast majority should. No MT-32 game should work.
For Sierra, you can refer to my list, I believe all games designated as General MIDI should work. Some late MT-32 games where GM support was added will work also, although for optimal sound it is recommended to use a MT-32 (or MUNT):
http://www.sierramusiccentral.com/assorted/Hardware.doc
(I believe these 4 games are the only qualifiers under [Some late MT-32 games where GM support was added will work also..]
Laura Bow II: The Dagger of Amon Ra
Police Quest I: In Pursuit of the Death Angel (SCI Remake)
Quest for Glory: So You Want to Be a Hero (SCI Remake)
Space Quest IV: Roger Wilco and the Time Rippers- maybe CD version only?
There is possibly some games with after-market support that would also qualify for this list, such as Eco Quest 1. But again, it's a MT-32 game, so MUNT would be the preferred option, along with your Sound Blaster.)