It was released on the system 12 board (same as erghiez, tekken tag, soul calibar etc…)
And was supposed to be a japan only release.
The game has… unique characters to say the least. Including a professional wrestler, someone who appears to be a vampire, a hawk, tiger and shark, an alien, and a knight with a lance (who is a bonus stage character and a hidden last boss).
This game is more 3D than SFEX. ie side steping, on a small platform with walls (similar to TK4/SC but no ring outs).
Allen is a hidden midboss (IIRC he justice fists through a wall onto your enemy and you fight him).
Some moves have changed for blair and/or she got new moves.
Some of the new moves where featured in EX3 as moves you could buy for the editable character Ace (galaxy, fairy gift, killing bee to list a few).
All and all, its a pretty fun game, that feels like a mix between RS and SC.
For most people who don’t like EX, they find it superior to it, while I find it a bit too loose (hard to describe it) but fun none the less.
For the musical score, I have no idea who did it. But seeing how both EX and this game were made by ARIKA, it stands to reason that it could be the same sound team for both games.