Any idea how I would run this on Ubuntu?

I installed it through wine, but would obviously need dosbox to start it. I adjusted the mount paths in the conf to match my machine, but all I get running it through dosbox using the two conf files provided is an exception error.

Has anyone played this on Linux? German version, mind you.

Which one? What sort of exception? In particular, is it dosbox itself or the game that's giving an exception? I don't use Ubuntu, so I have to ask: what version of dosbox? Did you remove the "overlay" mount (used for Galaxy cloud saves, not available on Linux, and you'd be better off using unionfs-fuse or something like that if you want overlays, since there are some issues with dosbox's overlay)

I use the default dosbox configuration myself, with slight customization, and only use the *single.conf file contents from gog. The only config options I copy from the main/shared config are the CPU cycle limits. I also enable mt32 for roa1-2 and correct the paths in game.inst in roa3. This has worked without issue for years.

I run the series via Lutris. No issues in RoA1 and RoA2 so far, but Riva is still misbehaving.