I'm not sure exactly when the crossover craze got started -- perhaps in 1996 with Capcom's X-Men vs. Street Figther -- but it seems like they're popping up everywhere; Super Smash Brothers, Capcom's Vs. series, Dissidia: Final Fantasy, and games like Cross Edge are just a few examples. If you're a Japanese company that isn't making crossover games, you're not getting invited to the prom.
Nippon Ichi and Gust are adding to the list with Trinity Universe (PlayStation 3 exclusive), which will hit Japanese shelves in September, courtesy of publisher Idea Factory. NIS and Gust are apparently getting double prom, though, since this isn't the first time they've all gotten together -- they teamed up for the mediocre Cross Edge as well. Their latest offering features tons of Atelier and Disgaea cameos and some original characters.
Anyway, there is a rather long trailer for Trinity Universe below the jump. The first, say 3:30, is just character introductions. I'd suggest skipping it unless a.) you speak Japanese and b.) you really like watching Prinny and Etna talk to each other. After the pleasantries, you can catch a glimpse of the actual game: 3D dungeons, a battle system that involves some sort of chain mechanic, and lots of shiny explosions.
So -- did any of you like Cross Edge enough to be interested in Trinity Universe? More importantly, what would your ultimate crossover game be like?