Posted July 05, 2018
It's a grey area, unfortunately. The thing is that the main purpose of this list was to find out which games on GOG have internal achievement systems, comparable to, but indipendent from, Steam/Galaxy/XBLive achievements. Eschalon has optional challenges, but I don't know if they could count as achievements as we know them, The Saboteur had something similar (playstyle-related challenges which give you special perks when fulfilled). There are borderline cases like these, usually with older games.
Desmight: They actually sound like the "challenges/feats/achievements" of Indiana Jones and the Fate of Atlantis, which are off the list because they're pretty weird and are not what most people consider achievements to be in the modern age. I'll look into it as soon as I can, thanks for bringing it up!
MarkoH01: No, Indiana Jones was left of the list because it only gives a certain score for things you have to do while playing the game (much like the old Sierra games did). Achievements have nothing to do with the fact where they are shown, Iif they only show on Galaxy or Steam does not matter - there are many games which store their achievements in a list inside the game. Most people define achievements as additional tasks that are not required to finish the game but are optional challenges leading to additional playtime and/or replayability. Yes, I know that some games also show achievement that cannot be missed because they are part of progressing in the game but I never saw a user beingt happy to unlock such a kind of achievement.