I just got them now that they were made free, so...

Right, I got them, too. I could have looked without making some general assumptions. ;-I

The Cat Lady -- The GOG version has "Soundtrack" and "Ultimate Original Video Game Soundtrack" included as goodies, but neither of those have the vocal tracks heard throughout the game. The Steam version has those vocal tracks available as a paid DLC (The Cat Lady Album (Music From The Video Game)).

According to this: https://www.gog.com/forum/prodigy_tactics/gog_version_out_of_date/page1

Prodigy tactics is lacking updates.

I recall the devs saying that the game is indeed matching the version of steam.
According to their devlog on steam forums, and the character content, it seem to be the case.

GOG Version is listed as Update 6, steam only lists Update 5 until now?

It seems we already have the upcoming Update mentioned in steam forums for end of december.

Oh I see, my bad!

Some time for a little update:

- Missing paid Disco Elysium DLC Soundtrack and Artbooklet which is available on Steam.

- Missing Edna and Harvey: The Breakout remake Anniversary Edition which is available on Steam.

Missing updates:
- Mable & The Wood (Steam: 2019-12-13, GOG: 2019-11-07)

- Automachef (Steam: 2019-11-28, GOG: 2019-11-07, offline version even 2019-09-10 only)

- Shovel Knight Showdown (Steam: 4.0B - Spinning In The New Year, GOG: 4.0a hotfix)

- Shovel Knight: Treasure Trove (Steam: 4.0B - Spinning In The New Year, GOG: 4.0a hotfix)

- Shovel Knight: King of Cards (Steam: 4.0B - Spinning In The New Year, GOG: 4.0a hotfix)

- The Swords of Ditto: Mormo's Curse (Steam: 2019-11-08, GOG: 2019-06-17)

- Tangledeep (Steam: 2019-12-27, GOG: 2019-12-09)

- Etherborn (Steam: 2019-10-02 (1.0.2), GOG: 2019-07-19 (1.0.1))

This might be true, but it is a different game. Even on Steam you can still buy the original and the remastered one costs much more. Also, it has been released this month (early December) on Steam as well, so it might arrive here as well a bit later.

bump again

Dying Light - Retrowave Bundle DLC ?

Oh yeah, a new missing one.

You're right Marko, it's a separate game, but in contrast to Steam users which get a special discount for owning the original, GOG users would have to pay the full price (or refuse to buy until it also arrives on GOG ;-) )

Thank you for keeping all up to date! Hope you and all around here had a happy Christmas time and I wish you all a Happy New Year! :)

PS: I did some more research and found some more inconsistencies. Partially, it only concerns a few patches, but due to missing patch notes, it is hard to determine the severity.
- Apsulov: End of Gods (Steam: 2019-09-24, GOG: 2019-09-09)
- Beholder (+ DLC Blissful Sleep) (Steam: 2019-09-11, GOG: 2019-02-04 (+ GOG misses languages Japanese, Turkish))
- Deep Diving Simulator (+ DLC Adventure Pack) (Steam: 2019-12-20, GOG: 2019-09-18)
- Divinity: Original Sin 2 (+ DLCs) (Steam: 2019-11-25, GOG: 2019-11-13)
- Ion Fury (Steam: 2019-09-20, GOG: 2019-09-18 (1.02))
- Remothered: Tormented Fathers (Steam: 2019-08-05, GOG: 2018-07-06)
- Retro City Rampage DX (Steam: 2018-12-03, GOG: 2017-05-25)

- Missing FLAC soundtrack files for Neverwinter Nights: Enhanced Edition - Tyrants of the Moonsea Official Soundtrack which is included in the Steam version
- Missing cover files for Neverwinter Nights: Enhanced Edition - Darkness Over Daggerford Official Soundtrack that were added to the [url=https://steamdb.info/depot/854961/history/?changeid=M:4527562429418865519]Steam version[/url]
- Missing Polish Artbook for Frostpunk that were added to the Steam version

- Missing free Beholder DLC Original Soundtrack which is available on Steam

It would be a different thing if the game would arrive here and the discount given on GOG for owners of the game is not given here however - this is just a missing game and therefore imo does not belong on the list.

Also, be careful. Neither gogdb nor steamdb is perfectly reliable.