Everyone should do this. It includes games like Amnesia and Limbo, and the extra funds go to charities.
More importantly Psychonauts, which reamins like the greatest game of all time.
Games are all DRM free (but you can get steam keys, ‘cause steam rocks) plus help out awesome folks.
Also, if after this you still haven’t played Psychonauts; then bad stuff and you’re a fool. (Leave me alone it’s late)