I don't have it, so I can't confirm it. All I know is that the base version has the manuals in its extras, but there is no indication about them in the Deluxe Edition. I don't know if GOG forgot to edit the storepage properly, or if they really forgot to include the manuals in the Deluxe Edition.

The game's English manual is also available in the game's installation folder.

Thanks, Grargar. Moved to Appendix B.

I'll nudge support to see if they're doing anything about my ticket. I'd appreciate at least a "No" reply if they can't/won't do it.

Thanks for letting me know - updated the relevant entry.

Moar updates. The manual (in English, French, German and Spanish) can be found in the "Manual" subfolder of the game's installation directory. That very same manual can also be found in the game's installation directory. Html versions of the manuals for both games can be found in the "help/manual" subfolder of the games' installation directory. Sure, they are probably lower quality than the ones posted above, but I have a feeling that GOG considers them good enough. That very same manual can also be found in the game's installation directory.

Thank you. Updated. That's more breathing space.

Do you have the games? Could you provide a copy of the HTML manual? I'll keep the link in the master list, unless the HTML version is of as good quality as the pdf one.

Yes, I do. Almost all the info I have provided about manuals in the installation folders has come from personal folder-checking. Here are the manuals:

Serious Sam The First Encounter:
https://www.dropbox.com/s/wzwizbqzyemtcw2/Serious%20Sam%20-%20The%20First%20Encounter%20Manual.zip?dl=0
Serious Sam The Second Encounter:
https://www.dropbox.com/s/dqzbpc1px8hiwp5/Serious%20Sam%20-%20The%20Second%20Encounter%20Manual.zip?dl=0

Thank you.

It appears to contain more info than pdf. But then the pdf is probably a true copy of the physical manual. I'll keep both in the list.

Thanks again for letting me know. The subtitle of the gogmix page should apparently rather say "Gogmix by Treasure and Grargar" given your contribution...

I presume the same applies for the Deluxe Edition of Xulima, since the only thing different there is some additional extras (do let me know if I'm mistaken)...

These are actually rather well hidden since the Help>Manual folder (especially the help part) isn't an entirely obvious place imo, as I'm used to seeing chm help files in such folders. I also have to remark that I see why GOG would think these are good enough, given that the 2nd manual is just the aforementioned html manual printed as a pdf, and the 1st manual is also a pdf that does not look very much like it could come from the original game (though I might be mistaken-I have no idea what the retail version of the game contained). And in regards to the gold edition, it might differ in some aspects from the original games, so I had it there more because it existed and it might help.
Anyways, modified the relevant entries accordingly, thanks again!

Correct. It's the same case for both editions.
Their actual location is indeed kinda hidden, but the manuals themselves are also accessible via shortcuts from the games' program folder on the start menu.

Updated the relevant entries with this new information -thanks again! :-)

The just-released Black Moon Chronicles has no manual in the extras, but, there is something pretty interesting written on the storepage:

Notice: Black Moon Chronicles has an HTML manual available from the Start menu shortcut for the game.

Is that a dig at us? :P

No, but yes and yes, but no. :P

Anyway, since you're here, could you please investigate the two following discrepancies?

Baldur's Gate - Siege of Dragonspear mentions 3 manuals in its extras, but none in its Deluxe Edition. Is that intentional?

Tropico 5 Complete Collection Upgrade has the manual in its extras, but the Tropico 5 Complete Collection doesn't. What gives?

Also, I understand that you may not be able to add some of the manuals from this list, but would it at least be possible to add the manuals mentioned in Appendix B of this post? They are already in the installation folder of the game and it would help to have them available in the extras without having to installing the game.

Just added the game to my gogmix, mentioning the notice. Thanks Grargar for mentioning this on the thread (though I noticed the notice myself as well) and Judas for (apparently) writing the notice in the 1st place!
Fyi, a better quality manual would obviously be preferable (especially by ZFR) but this is better than having nothing at all, so thanks @gog for mentioning the existence of this html manual at least...