Danc over at Lost Garden is performing an interesting experiment. He is creating some very high quality graphics and describing a basic game mechanic. Anyone who is interested is invited to take those graphics and core ideas and create a game prototype. In turn, what everyone learns from each prototype is going to be fed back into the game description and further games created. It sounds like a very interesting and fun experiment... If you enjoy building indie games as well as playing them, go grab the graphics pack and create something!

Here is the original post with the challenge, and here is a follow up post.