What I'm talking about is this:
Hey fans! We are making a new game and want you to help us design the ________
Or
Hey fans! We are having trouble with ________. Think you can do better?
What made me think of this is:
I'm not a fan of metal (most of the time), but I couldn't help imagine how crazy it would be to play against those two witches with that remix playing in the background. It would be intense!
So if say, Nintendo, came out with some songs for the next Zelda and was like..."Hey fans! We want you to try your hand at remixing this song for a huge battle and make it as epic as possible!" We could listen to that caliber of work or better in the actual game.
Same could go for character designs or art style or ancient language or animals/npc's/names/places etc. etc.
The eventual game could be awesome.