A lot of people don't like it, but I have fond memories of X-Men Mutant Academy (the first one. Never played the sequel).

For obvious legal reasons, NRS could never make such a game, but I think the X-Men lend themselves well to a fighting game, or maybe that's just my nostalgia from Mutant Academy. Either way, the concept is good. I don't think there's a person among us who wouldn't want an X-Men version or even a straight Marvel version of INJUSTICE. The fact of the matter is that the people who made INJUSTICE work for the Dancing Frog while Marvel is owned by the Mouse. They don't play together.