Ian from thanklessgrind has done some data mining to determine what percentage of people finish games. Using Giant Bomb's acheivement database, it's possible to see what percentage of their users have gotten each achievement. From then it's only a matter of working out which achievement is associated with actually beating the game. With all the hard work done, can anyone guess which game was the most completed game of 2009? It rhymes with 'trodden lawnchair'.