Note: this post is from 2007, outbound links may be broken.
MyGame: create and share flash games
MyGame is a new social gaming site that brings together user generated content, casual games, and revenue sharing.
Duncan Riley writes:
MyGame users can play existing games or develop their own games using a game builder. Users pick a game template, personalize it with text, sounds and photo, then start playing. User generated games can be shared on social networks or added to blogs and websites.
Link via TechCrunch