A little known fact about the PlayStation 3: it can support seven controllers, although we can't think of a single game that's taken advantage of this rather unique feature. When I spoke with Omar Kendall, director of the upcoming PlayStation All-Stars, I asked why his game didn't support more than four players. Given there's no need for split-screen, it seems like a perfect candidate to be PS3's defining seven-player game. He didn't answer my question, but did offer a rather odd tidbit about the game's development.
PlayStation All-Stars: Battle Royale wasn't always a fighting game, he revealed. SuperBot was tasked with creating a game that could bring PlayStation characters together--no matter what the genre. Before it turned into the four-player fighting game it is today, it was actually an eight player (4v4) capture-the-flag-inspired action game.
As in Battle Royale, the action took place on a 2D plane. Different characters had different abilities, making them better suited for taking different "positions" on the screen. As in a game of soccer, some characters were more apt at playing "center field," whereas others would be more aggressive, taking a forward position. Kratos, for example, would probably be an offensive character; whereas Fat Princess would be a defensive one.
Given SuperBot's background in fighting, the game eventually turned into the 2D fighting game it is today. Still, it's a tad disappointing that only four players can play at once. Imagine how truly chaotic it would be to have seven players on one screen, all brawling.