Dax Ginn, marketing manager for Rocksteady, has said the reason Batman: Arkham City has so many villains is due to the game's sizable open-world.
Speaking with Joystiq, Ginn said this was another reason the team included Catwoman as a playable character, because not only did things need to be mixed up a bit, but sometimes, it's just fun to be the bad guy.
"It's not always fun being the righteous arm of justice, so we wanted to explore what it was like to be a criminal within Arkham City, as well. Catwoman became a great option to explore that," he said. "We kind of look around at other games, and it's obvious that some players like breaking the rules."
Ginn said with the game being open-world, it also made sense to fill it with more of Batman's famous enemies.
"One of the big issues with an open-world game is you don't have that same claustrophobic intensity, so that sense of threat just evaporates," Ginn said. "We then thought how we could offer the same sense of threat, but give the player freedom they've never had before. So without that fear, we knew we needed a load of villains to toss at Batman. We then made the decision that it couldn't just be Joker anymore -- we needed Two-Face, Riddler, Penguin and even Catwoman in there.
"The decision behind bringing in more Batman characters was driven by the call we made early on to make Batman: Arkham City an open-world game. Arkham Asylum is very tense, very claustrophobic, so you didn't need any more than to put Batman and Joker in that pressure cooker and just let them go at it.
"When we decided what we were gonna do for the second game, we knew people wanted to see Batman in Gotham; they wanted to see Batman in the streets. All these other decisions then became kind of necessary. One decision drove so many others."
Arkham City is out on Xbox 360 and PS3 October 18 in the US and October 21 in the UK. The PC version will release in November.