Using points like "uniqueness" or "fitting the environments" are frankly terrible ways to argue for quality in a videogame soundtrack.
Actually, they are pretty much the best arguments you can use. If a soundtrack does not fit the environment it's written for, then what's the point of it being there in the first place?
Like the Swing version of Beginning in the Saturn port of Symphony. What was the fucking point of that crap? I like it outside of the game, but it belonged on a special music CD, not IN THE GAME ITSELF.
Castlevania: Symphony of the Night (Saturn ver.) - Beginning (Jazz)(Digging those Youtube comments though.)
Similarly, if it's not unique and fails to sound apart from other items on the market, it will be similarly derided.
Uniqueness and fitting the environments are the FIRST THINGS THAT NEED TO BE CHECKED OFF.
"Does it fit?"
Yes.
"Is it boring and stale?"
No.
Mission accomplished.