Hello there, I also own Cognition GOTY and there are 4 separate episodes in my library. Unfortunately, this is how GOG organized the files for a few games (e.g. Wallace & Gromit as well) and they look like separate games instead of being merged into the same installer. I mean, you can't even buy them separately so what's the point?

Anyway. Can you install each episode separately from its dedicated library entry? If not, then you should contact support.

You have Galaxy to thank for that. Due to the obsession with pushing a client as "The GOG Experience (tm)", the offline installers of many multi-game collections have been split up (The Blackwell Quadrilogy is the same). What you could do (other than finding an older installer somewhere) if those particular games are "portable" is to install them then zip them up / create your own offline installer.

To GOG's defence, both of those games used to be sold as individual episodes. I don't know how GOG did it, but at least that's how it was elsewhere. Of course there shouldn't be any reason to do that anymore, as both of those games are sold as one complete game these days, I'm not aware of any store doing otherwise.

You're right, it could be done this way. But, shouldn't it be already taken care of by the store that sells them? Sounds too much of a hassle for me, especially if one of all episodes gets an update at a later time :) Really? I don't remember that. I had bought Cognition as one package for sure. Maybe I had never noticed it before.

In any case, this shouldn't be difficult to fix, both the episode merging as well as the library entries. All required info is in the database, so this could even help solve the more general problem with "complete" editions not being marked as owned in the store although all distinct entries are owned.

Well, i do have all the episodes, and i have already played the first one and about to install the second one.
but i thought i bought the "Game of the Year Edition" wich should be one single installer, with one unified menu, with all the episodes on it, and maybe other extras than just buying the old separate chapters.
are we being scammed?

Do you have a particular reason for that expectation or are you just assuming? If the GOG GOTY edition is missing something the GOTY edition has elsewhere then you should take it up with the developers. Ultimately GOG can only provide you what the developers provide them.