When a re-release gets unreleased
Phil "Shadsy" Salvador, at The Obscuritory, which reviews old computer games:
From time to time, I’ve gone back to older posts to add the “still sold” tag them, like Lighthouse: The Dark Being, which was officially re-released a few years ago. But there’s also an alarming movement in the other direction – games that go back out of release.
While GOG.com, Steam and the Internet Archive have saved a lot of old games for posterity (for now), they've only been able to do that for those games where they've got both access to the code and permission from the creator(s). Abandonware sites and emulators may be able to fill in some of those gaps, but the former are walking a copyright tightrope, and the latter may never be able to emulate the original hardware sufficiently for some titles (plus they have copyright issues regarding ROMs and boot code.)
It’s a great frustration that game availability can be so unstable that it toggles between those two options: official or unofficial, sanctioned or unsanctioned, working on modern devices or left for players to figure out for themselves.