My Game Theory
Jacket: Jacket, the first playable character, represents the majority of the gaming crowd. He is a psychopath who kills people simply because its fun and he was told to. This is what a lot of players do in video games.
Helmet: Helmet (the second character you play as) represents players who favor narrative in games rather than gameplay. Jacket and Helmet are the opposite ends of the video gamer spectrum. Since the story in HM doesn't make much sense, Helmet goes around asking other players (the two men he interrogates), how to quickly beat the game so he can see the ending. He rushes through the game and finally meets the people who have been calling him: the janitors.
The Janitors: The two janitors represent the game devs. Helmet meets them, asking them why they made this seemingly pointless game. They answer, "Because we had fun making it and we thought you would have fun playing it. Plus, look at all this money we're making!"
If you have your own theories or ideas to build off this one, post them here.