Cave story is a mostly digital game, which means that preserving every version can be hard, especially when some versions approach 10 years old. First let's go over version that are very easy to preserve: 1. Cave Story 3D and Cave Story+ (Switch) These were released physically, so the only way they can be lost forever is if every copy is destroyed, which isn't happening anytime soon. 2. Cave Story (Freeware) This is easy as it can be legally uploaded to any file sharing site imaginable and then it will probably be preserved until the internet goes away. Now let's go over the ones that cannot be obtained legally. 1. Cave Story (DSi) This one is so hard to find it might as well be lost media, despite many people just having it on their DS's. I have looked everywhere for a rom dump and emulator, but I can't find it. Even if someone here finds a rom of it, they can't share it due to it being illegal. It's a shame as this version is pretty unique compared to the 3ds eshop port. 2. Cave Story (Wiiware) This one is technically still obtainable, you just have to have a bunch of Wii points sitting around, which not many people have. I actually got this one before the wii shop closed, so it's not lost to me. Even if you never bought it, It's not hard to find a rom dump of it, and dolphin can run it fine. You can even upload the wad on to an actual wii via homebrew (however I haven't been able to) The only version that is under threat of going lost is Cave Story (3ds) as the eshop will close eventually. This will be a shame, as it's the only way to have the original sprites in stereoscopic 3D. Hope that rom get dumped somewhere in the mean time. I don't see CS+ (PC) under threat of being lost, as I suspect steam is here to stay, and there is a dam free version on Humble Bundle. What are your thoughts?