Sales Discontinued

Ultimately that is kind of the MSX-curse. A small standard where expansions make it bigger. Yet not everyone has those expansions, so software makers often aim at the common ground where high-end expansions rarely get used. If ever someone makes a production that uses high-end expansions, you get exactly this problem you mentioned.

As an alternative, there's emulation. And that raises the question for which audience we're all making software. For the handful of owners of the true hardware who also own the more exotic expansions? Or for emulator users? Meaning these games essentially become PC games that use MSX limitations... It's kind of a philosophical question.

Many users own those expansions plus there are also emuladors. Not a problem at all I would say.

Moonsound is still a lot rarer than SCC or MSX-Music.
It's a good thing to use the best hardware available but it would have been even better if we could have played it without this rare hardware (like some Konami games work with or without SCC).
That said, it's up to the creators to decide who their game is aimed at.
We can regret it, but we must respect their choice.
Be able to enjoy this excellent game via an emulator, it's already not that bad.

Yeah well, back in the day PC's came without a sound and video card. You needed to add those and it was not strange soundblaster or 3dfx were used by the most recent games.

Good software that makes uses of the extensions is an incentive for people to upgrade the hardware.

Supporting multiple sound cards was a commercial decision. I am not making money on this. I made this because this it the way I like it to be. I never will use it myself with the "PC internal beeper".

But anybody is free to redo the tracks in pt3 and a fmpac version. Send them to me and I'll include it. With a little work it can support multiple players.