Methodology? This ain't rocket science. If Shantae is not eligible for this list, then neither is a raw Gameboy ROM. Ease and usefulness have nothing to do with it.

The problem is not emulation, every DOS game here is emulated, Nox Archaist is on an Apple ][ emulator etc.
The reasons are:
1. Keep the list reasonable without titles that - a priori - will never come to PC;
2. The game must be released somewhere in a format that is playable on a PC out of the box. For example: Streets of Rage 1-3 are playable on a emulator, but if you buy them on steam, you can play them out of the box, no third-party software needed.

Super Lone Survivor, a remaster of Lone Survivor: The Director's Cut, was apparently released half-a-year ago.

Thanks! Missed this one completly, surprised it wasn't advertised more in general.

Added:
Super Lone Survivor

Removed:
Warhammer 40,000: Dawn of War - The Complete Collection

Railway Empire 2 seems to be out but not here, right?

Also where do we stand on Early Access? The Outlast Trails is available elsewhere in this unfinished state, it seems!

Thank you!

Added:
Railway Empire 2
The Outlast Trails

These games did have PC ports, just apparently never added them to the list.

Added:
Arkanoid
Arkanoid: Doh It Again

https://www.gog.com/forum/general/completionists_list_of_missing_games_from_gog_series_v2/post735
It's true that it received a PC port but, as far as I know, it was only released in Japan:
https://gamefaqs.gamespot.com/pc/328332-arkanoid-doh-it-again/data

Yeah true, I was thinking about that - keeping "regional versions" only on the list. I couldn't remember what the consensus was on that, but looking in the actual list there seems like there might be some old remnants of that (some German-only DLCs for one game for example).

Also in general, having issues updating the original post for some reason - will add Arkanoid as soon as possible!

Star General has been released and can, thus, be removed from the list:
https://www.gog.com/en/game/star_general

In addition, Contra Anniversary Collection has also been released without a newspost mentioning it:
https://www.gog.com/en/game/contra_anniversary_collection
The original list used to include non-English DLCs, but not non-English base games.

As for Arkanoid, I did say that the new game includes a port of the Arcade original, which is superior to the DOS version, so it might not be necessary to include it.

Thank you! And yeah, I'll leave Arkanoid and its sequel out for now.

Removed:
Star General
Contra Anniversary Collection

I noticed back in the day a number of notable console games received PC ports but it was for the Korean market. Farland Story and 1-3 of the Metal Slug series as I bought the latter collection there for $20 at the time. Played flawlessly on PC to me so it seems it was an excellent port.

Removed:
Crusader Kings II

Arsenal of Democracy is part of the Hearts of airon series and it can also be removed.