At one point in time, RARE's N64 classic GoldenEye was getting a full-on remake. Then, because of business dealings and other behind-the-scenes negotiations, the project was dead in the water. The sad part is that the project itself was nearing completion. While it may have never seen a public release, those who work to preserve game history have come upon a content-complete build of the game.
If you want to see what the revamp would have looked like, you can't get any better than the video above. It's a full run-through of the game, showcasing all the missions you know and love. What a shame this one never made it to market.