The Quake II PSX mod on ModDB brings the PSX edition of Quake II to PC, updated to work with the remastered PC version of Quake II (thanks jtucker). This has some extra bona fides, as it was created by Paril, part of the Nightdive team that developed the Quake II Remaster. Word is this includes all the content of the PSX edition of the classic first-person shooter with some tweaks and enhancements with the hope of an even better experience. This trailer shows off the mod, warning that "the footage in the video is from a lower quality lighting bake and not fully representative of the final quality of the lighting." Here's more:

A fully-featured port of the campaign of Quake II PSX for Quake II Re-release. Play through all 20 levels of the PlayStation port, remastered on the 2023 Quake II Re-release engine.

• Meticulously recreated by hand; this isn't just a simple copy & paste port. The PSX version of Quake II used an entirely in-house engine created by HammerHead, and due to various technical differences it ended up being simpler and more efficient to simply reproduce the maps using the originals as guidelines. An in-depth explainer on how this was done will be posted here in the future!
• Enhanced encounters; Quake II PSX had much less intelligent AI, several bugs that greatly affected gameplay (such as difficulties being assigned wrong for certain levels, causing more monsters to spawn on Easy instead of Hard), and many limitations compared to the PC version. We took the time to set this right! The monsters use the new, smarter AI of the re-release to its fullest extent, making the game less about fighting against the dated digital control scheme of the original and more about fighting the Strogg.

• Thoroughly tested; with a public alpha period tested in a few select circles, the community has been instrumental in making sure that this release goes as solid as possible.
• Surprising additions; instead of being a 1:1 clone, we decided to improve a few areas of the original port that we felt were lacking. The majority of the campaign should be recognizable to anybody who has played the PCX (or even the PC) version, but a few choice levels received some upgrades to their visuals, encounters or flow. There may even be a few new secrets to discover...
• Improved monsters; all of the monsters gain their re-release improvements as expected, but the two exclusive monsters, the Guardian and the Arachnid, have been tweaked with a new arsenal and mechanics to make them stand out even more.