From their website:
"The Experimental Gameplay Project: create 50 to 100 games in 1 semester. New games every week.
each game must be made in less than 7 days
each game must be made by one person, including all art, sound, and programming
each game must be based around a certain "toy" ie. "gravity", "vegetation", "swarm behavior", etc.
What?: Some games are below, some good, some crappy, all experimental. Have fun!"
Some are 'nongames' (possibly because of the "toy" rule), and some are really good ('On a Rainy Day', 'Gravity Head' and 'The Crowd' are my favourites).