The zip file is incorrectly formatted. You need to put all the files in the zip file, in a subfolder named Meowdiver.pdx
Such as : Meowdiver.pdx.zip / Meowdiver.pdx / All the files
In contrary to the current : Meowdiver.pdx.zip / All the files
That is… not really the proper way to sideload games om the PlayDate.

Yes, you could still manually boot into Data Disk mode and manually do that yourself, but I don’t see why you couldn’t just upload updates the same way, except for a mistake in the buildID file. Even in that case, yoi could just delete the previous game in the sideload web page. The website tracks the different version you’ve uploaded.
Actually getting a 413 Entity too large error on the Playdate sideload page when trying to import your game. Thankfully, I can still sideload it with the other ways (thanks for detailing the alternative methods), but you may need to try to get it under 200mb zipped. I managed to just repackaged it with heavier zip compression methods for 198.4Mo, so this could also be an easier fix. Additionally, there’s a mistake in the pdxinfo, you added duplicate entries for buildtime and pdx version which cause errors.
I third the glowing issue. CachyOS (Arch Linux based) with a AMD Gpu too. I did tried the native Linux version and the Windows version to no avail. However ! The Web version doesn’t have this issue ! It isn’t ideal however as you say, so I prefer playing with the glowing artefact until something can be found about it. If there’s any way we can share rendering logs or something, tell us !
I quite like it, and it works flawlessly on Linux via monado (Haven’t tried with SteamVR). Tested on a Valve Index.
However, a couple of points to note :
GPL2 https://runningwithscissors.com/the-original-postal-has-been-made-open-source/ https://github.com/RWS-Studios/POSTAL-SourceCode (Previous original repo, which according to some was a more recent version of the re-uploaded source-code https://archive.org/details/postal_source https://github.com/RWS-Studios/POSTAL-SourceCode/issues/1 Pull request available from this repo too https://github.com/RWS-Studios/POSTAL-SourceCode/pull/2)
No, of course. The Krotchy and Kunny mascots aren’t considered as NSFW, even if their appearance is suggestive. It’s mainly in case of more graphic depiction of gore (Outside the unrealistic cartoon usage. More an issue with very extreme gore, or realistic ones), nudity and pornographic explicit content, and life-threatening content (Epilepsy, loud noises, screamers, psychologically shocking content). We know that the original games in the Postal Series aren’t really for the public of all ages, so we would rather not restrict people from doing family-friendly games. We expect people to use their common sense to not go overboard with it.