I watched this on YouTube the other day. Another beautiful example of the creative power yielded from building within constraints.

In case anyone is interested, this creator built a remake of Portal for the N64, uploading a really cool set of videos describing the work that went into building it.

He's since stopped to work on his own IP, I believe that the issue was that Valve couldn't allow it because they'd never get Nintendo to agree to it. Something along those lines, anyway.