James Lambert has been working on a Nintendo 64 version of Portal for many years. Unfortunately, it is not the whole game but rather just the first 13 levels, and while these levels have been available before, it is only now that they have left the beta stage for this version.
The levels are fully playable on the Nintendo 64, but it will be a while before the rest of the game arrives. Lambert says in his video that he needs help with the project to complete it. If you want to test this demake, it can be found here. You need a Nintendo 64 or an emulator to be able to test this version of the game.
<social>https://www.youtube.com/watch?v=sb3nHlsBBpg</social>