Fan Created Game Bringing Portal To DS
If you're unfamiliar with Portal lore, Rattman is best known as the man who wrote "The cake is lie," all over the walls of Aperture's laboratories. You can learn all about him here.
The duo have managed to create a working build of the game, which you can check out here. You will need a flash cart if you want to check out the game. The build also includes a level editor.