I was about to say "No Termina game at all" since I don't like the idea of just Termina by itself. The entire appeal of the land was the fact that it only had 3 days left to live, and it brought out the true selves of the people within. Without the imminent threat of the moon, it wouldn't have the same appeal as MM.
But...
if they did a crossover between Hyrule and Termina, where people come in contact with their alternative selves (and not just Link and the Skull Kid) then that's actually a really cool idea. I imagine the two Goron races would get along just fine, and the Zoras would hold one fantastic concert, but there would undoubtedly be tensions between the Hyruleans and Terminans. I imagine the king would have a few choice words with how the mayor is running Clock Town, and Gorman would tell Ingo off for staying on the ranch instead of making a name for himself. And even beyond that, their religions would be in direct conflict. We know the ancient Terminans despised the Golden Goddesses (evidenced by Stone Tower Temple being a giant "Screw You!" to the Trinity and extolling their devotion to their four male Giants), and it's very likely the modern Terminans would take up arms against the Hyruleans because of this. Heck, this would be the all-out war I want to actually see in the series: not between good and evil but between humans against humans.