Personally, I think it might be the forgotten characters gone bad, creating this twisted evil world, and you play as Mickey and have to stop it. It mentioned something about erasing the levels and stuff. I noticed that theme in the scenery... Paint brushes, tubes, and that God damn "paint thinner" bottle. maybe your job as mickey is to erase the conquered levels and remake them into the pretty happy stuff we normally see?
Maybe that Goofy and creepy robot with the Mickey ears aren't the real deals but some kind of by product of the twisted world.
Or, maybe thy are, and you make them normal again after you beat them, or after whatever. after you redraw them.
This game concept with just the minimal info and concept art we have, could still go MANY ways.