Well, I won the second game through Steam, so that's where mine is located. However, I plan on eventually purchasing it on GOG as well, so I can have the DRM free version.
Thanks for the info, Ana. Looking forward to it.
I, too, haven't completed the Deponia games yet because my backlog of unfinished games is too large. I've been slowly going through all my games, which includes some replays, but I'll get there eventually.
Anyway, I really like what little I've played of the games so far, and I'll definitely pick up the third through GOG so I can have the whole collection.