There's a reason why Mickey hangs out with Donald and Goofy.

Yeah, I never got what Mickey's character suppose to be. Donald is angry, Goofy is, well of course, goofy and silly but I can't even discern any personality from Mickey.
The only thing that stands out for me is the scene when everyone though Goofy was fucking dead, he pulls his keyblade and says "They'll pay for this!" but then again Kingdom Hearts is most certainly outside of Disney canon and for the best that is.
…that scene was the most fucked and gratuitous crap KH ever had and it's one of the reasons I love this dumb franchise.