What is a language game and what was Wittengenstein's "mistake"?

http://www.youtube.com/watch?v=r0cN_...eature=related
http://www.youtube.com/watch?v=PIhl9...eature=related
http://www.youtube.com/watch?v=ILlvG...eature=related

It's a very funny play around wittengensteinian thoughts.