Finding prototype and undistributed copies of retro games has turned into a modern day treasure hunt. Finding such a gem can result in your copy selling for thousands or even tens of thousands of dollars.
Here’s the story of a long-lost Nintendo DS game that was finally found. It was distributed to various McDonalds throughout Japan to help train employees. Follow the fun adventures Nick Robinson had tracking this down, buying it, and then finally playing through it.
Or, if you want, you can download a copy yourself and play it on a DS emulator. I applaud Nick’s values of not seeking profits first, but preservation by offering copies for free.