Arrogant, bloated ego, snide, and in general encompasses the exact stereotype you'd associate with a wanky independent developer who thinks his shit doesn't stink. I've never met him, so I don't know, but I do know a couple of people who have and not a single one had nice things to say.
Indie Game: The Movie also only focuses on Fish's side of the story, in regards to his fallout with his business parter. The original cut of the film states that Fish's business parter asked not to participate in the film. This is inaccurate, and was later revised to state he was never asked at all. It's a documentary that only shot one side of a situation and ignored the other.