Jun 21, 2012
It's relatively recent that the website allows you to upload your games, so most games made prior to September 2011 can't actually be played, because they're trapped on your computers.
Don't worry if your game is a work in progress; if it's more advanced than MOVE RIGHT, it totally belongs.
Here are the new (old) challenges you can upload games to:
The Pong Challenge, Fall 2008 Edition
The 8-Bit Challenge
The Shmup Challenge
The Tower Defense Challenge
The Collaborative Game Challenge
The Facebook Game Challenge
The Asynchronous Collaboration Game Challenge
The Budget Crisis Challenge
The Photos Challenge
The Genres Challenge
The 3D Game Challenge