Commonly considered to be one of the best games of its era, it's hard to say something new and worthwhile about Arkham City. But I'll try.

Rocksteady managed to combine the seemingly incompatible Beat em Up, Metroid, and Open World Action-Adventure genres, setting bars that games in those disparate genres have since struggled to reach. The game's hybrid of movement, stealth, and combat is reminiscent of the Assassin's Creed series, but far surpasses any game in that series. The synthesis of Batman series elements is successful, creating new versions of characters that are both recognizable and appropriate for this setting. Batman's natural abilities make traveling the Arkham ghetto more intrinsically gratifying than most games can offer.