[jmyc]

Related: genetic algorithms to play video games. I can't find the exact one I read about before, which was for Super Mario Bros., but searching for "mario genetic algorithm" leads to a number of papers, videos, &c.

[ihsw]

There are a[1] couple[2] on YouTube.

[1] http://www.youtube.com/watch?v=qYluZRwrw9w

[2] http://www.youtube.com/watch?v=DlkMs4ZHHr8

[pudquick]

http://julian.togelius.com/mariocompetition2009/

Similar, but more interesting