Awesome game. (211/219 people on Play have rated this 4* or 5*! They can't all be wrong)
Just look at some of its accolades:
Game Informer named Arkham Asylum "Game of the Month" in its September 2009 issue.
Giant Bomb awarded Arkham Asylum their Multiplatform Game of the Year 2009.
Games Radar awarded Arkham Asylum the Game of the Year award, narrowly defeating Uncharted 2: Among Thieves.
GameTrailers named the title both Best Action-Adventure Game and Biggest Surprise of 2009.
It won the British Academy of Film and Television Arts (BAFTA) award for Game of the Year as well.
"Outstanding Character Performance" (for the Joker), "Outstanding Achievement in Game Design", "Outstanding Achievement in Adapted Story" awards for the 13th Annual Interactive Achievement Awards from the Academy of Interactive Arts & Sciences, and nominated for "Outstanding Achievement in Animation", "Outstanding Achievement in Original Music Composition", "Adventure Game of the Year", "Outstanding Achievement in Game Direction", and "Overall Game of the Year".
The video game was also nominated for several Game Developers Choice Awards including "Best Game Design", "Best Writing", and "Game of the Year".
GameSpot awarded Arkham Best Atmosphere and Best Use of a Creative License in their Best Games of 2009 Awards.
...AND...It's less than a tenner....what are you waiting for?!!