2009's Batman: Arkham Asylum, developed by Rocksteady, is a stealth based action game based on the Batman license. The game follows the adventure of Batman as The Joker takes over Arkham Asylum, letting all of the inmates loose; these include fan favorites such as Scarecrow and Killer Croc. Aided by Harley Quinn, The Joker plans to unleash a virus that turns everyone into mutant freaks like Bane.
The game is graphically gorgeous, with a very dark and eerie tone. Everything is black and shiny and the atmosphere in the game is next to none. The game is very much in a darker, grittier Batman setting. The gameplay consists of action and stealth; both of which are extremely fun and masterfully easy to grasp. The game has a flow combo system that makes it easy to chain 30x combos whilst taking on tons of enemies at the same time. These combos can be upgraded - along with your gadgets such as the batclaw and batarang - via the xp system, which is obtained through killing enemies and completing challenges. The game is somewhat open world with many areas to explore and all of the areas feel different enough so the game isn't repetitive.
Boss fights in the game consist of many favorite Batman enemies and they are a blast to play. You battle Scarecrow in a nightmare land on multiple occasions and Rocksteady do some really interesting narrative things during these segments as well as providing fun little gameplay breakups from the main game. The stealth in the game is also surprisingly intuitive and it is easy to access unlike other stealth based games such as Splinter Cell or Hitman. Story in the game is also conveyed Bioshock style through the use of collectible interview tapes as well as character biographies which are unlocked after completing riddler challenges and collecting riddler trophies hidden throughout the world. Therefore, as well as the main game, there is plenty to do in Arkham Asylum.
As well as the main game, there are challenge modes which can be accessed from the main menu, although I didn't spend a lot of time with these because the main game was so enthralling on it's own.
Overall, Arkham Asylum is an extremely polished, extremely enjoyable game. The PC port, which I played, is phenomenal and I had no hiccups or technical difficulties at all. The game isn't too short or too long, taking me around ten hours to finish so it won't take up much of your time. If you enjoy Batman, or even enjoy action stealth games, Arkham Asylum is a must buy.