Crossovers

What do you think of crossover games? (this can include full on crossovers, or even just characters from another game series appearing, or something like that)

I love crossovers. It's always really interesting to see the worlds and gameplay styles of 2 games put together and see what happens. Although, they don't seem to happen as much as I'd like them too. There's definitely some crossovers I'd like to see happen, but I know never will. (where's that Metroid and Star Fox crossover? )

There a mixed bag with some being good and others being bad. The reason why they don't happen much is because, it's hard to mix 2 worlds into one game.

^Yet SquareEnix does it so wonderfully mixing Final Fantasy characters in with Disney characters into their own unique little world. :p (I'm talking about Kingdom Hearts; here. lol)

Personally I've played a few cross over titles but from what I can see usually they're pretty good. Not to say there aren't some bad cross over games; I'm sure they're out there.. I'm just saying that I have yet to come across one is all. xp

I do really want to play the Ace Attorney X Professor Layton crossover, that game looks pretty amazing. I generally like crossovers, and some of those crossovers are even my favorite games.