Probably not all entirely original....

track1 - sounds a lot like ZARDOZ.CMF (1990, also appears in Zeux) but trimmed
track3 - DARKMOON.CMF (1990, also appears in Zeux)
track4 - BARDOM4.CMF (1991, also appears in Outlaw 1994)
track5 - DUNGO.CMF (1992, also appears in Zeux)
track6 - MOONLIGH.CMF (1992)

Many thanks, this is quite awesome.

I took your hint and found another one: track 9 - BALI.CMF
I also ran into BARNDOM6.CMF which matches track 4 too.

Was quite surprised by the way that DUNGO has a dedicated page about it...

Thanks to the wonderfully useful details provided by @leileilol (I really didn't have a clue where to start),
I think I have a summary for the tracks, minus track2:

Track 1 - Title ditto - while it sounds very similar to the introduction from ZARDOZ.CMF from 1990, and even uses the same instruments, the MIDI events differ, beyond simple reordering.
Track 2 - Introduction
Track 3 - Background music - DARKMOON.CMF from 1990 (probably from "CMF MUSIC COLLECTION FOR SOUNDBLASTER", 1992)
Track 4 - Background music - BARDOM6.CMF from 1991 (probably from "CMF MUSIC COLLECTION FOR SOUNDBLASTER", 1992)
Track 5 - Background music - DUNGO.CMF by Dan Froelich
Track 6 - Background music - Piano Sonata 14 (aka Moonlight Sonata) by Beethoven (probably MOONLIGH.CMF which came with Sound Galaxy NX sound card software)
Track 7 - Background music - Nadia's Theme by Vorzon, Botkin (probably NADIA.CMF which came with Sound Galaxy NX sound card software)
Track 8 - Background music - Silent Night, Holy Night, a Christmas carol, sounds identical to SILENT.CMF from 1990 ("CMF MUSIC COLLECTION FOR SOUNDBLASTER", 1992), only simultaneous MIDI events are in different order
Track 9 - Background music - Bali (Ha'i?), probably BALI.CMF which came with Sound Galaxy NX sound card software
Track 10 - Background music - The First Noel, a Christmas carol, sounds identical to NOEL.CMF from 1990 ("CMF MUSIC COLLECTION FOR SOUNDBLASTER", 1992), only with several phrases repeated, resulting in a longer composition, and those matching having simultaneous MIDI events in different order
Track 11 - Background music - Hark! The Herald Angels Sing, a Christmas carol, sounds identical to HARK.CMF from 1990 ("CMF MUSIC COLLECTION FOR SOUNDBLASTER", 1992), only with extra (unused) instruments added to header, and simultaneous MIDI events in different order
Track 12 - Background music - Bengawan Solo, an Indonesian song (probably BENGAWAN.CMF which came with Sound Galaxy NX sound card software)

UPD: Oh, ZARDOZ.CMF usage in games apparently has quite a history as well.
UPD-UPD: Figured out Dark Moon was one of the official AdLib, Inc tunes that people could put into their Jukebox program.

Interestingly, after having had read on the origins of the tracks found with the game I have "discovered" the original Ad Lib music, and was just blown away with the quality and the compositions. I only got my sound card much later, and always thought Adlib was just a less advanced SB predecessor (obviously I never owned a MIDI synth module, like a Roland), but it turns out I was wrong and FM music started out really great and impressive on PC.

Now, with this particular game, I am actually tossing out classic and pop pieces and replacing them with CMF versions of those end of 80-s tracks, most non-surprising originating in Ad Lib's New Age Echoes.