Just a heads up.
A rather big feature called Treasure Scrolls are locked behind online in this game.
Treasure scrolls are special scrolls that can only drop and be activated when you are playing online.
They can contain either treasure hunts or bounties.

Treasure hunts require you to go to different places and find/collect the treasure pieces. After you've collected all the pieces you will automatically receive the rewards (like the challenges).
Bounties require you to go to several places and kill stuff (special bosses). Same as the treasure hunt, once you fulfill all requirements you get your rewards.

Very disappointing to find out that such a big and nice sounding feature are locked away behind online :(
One would think that this sort of thing wouldn't appear in a game that's being sold on gog.

Since a lot of peploe seem confused about what in the game is locked away by drm here is the rundown.
The DLC is coming to gog as separate downloads
"The Gift of Gear", whic is a unlimited health potion is also being patched in to be avalable offline.
However the Treasure Scrolls, which are unlimited mini quests are only available online, which sucks.