Superhero games are really hard to get right, because you want the protagonist to have his or her signature powers without making to game too easy. The European PlayStation Network Store has updated today with a demo of Batman: Arkham Asylum, which has an interesting mix of combat and stealth mechanics. It’s nice to see that Rocksteady Studios hasn’t attempted to develop a purely combat-focused game – doing that hasn’t really worked in superhero games in the past.