I just installed Unepic (GoG version v1.51.11) on Linux (Ubuntu 20.04).
The installation worked well and I can play the game in single-player mode.

However, unlike in the windows version, there is no "Multiplayer" option in the main menu. Neither to create a game nor to connect to an open game.
What is wrong here?
Is there some dependency I need to install for networking?

I would like to join a game in the same LAN.
Could you give me some advice?

Kind regards

Nearly 4 years and no reply. Such community. Wow.

On the store page it clearly states that Multiplayer is Windows only.

I don't understand it either, and I'm not a fan of that decision. However, you could probably just run the Windows version under WINE/Proton with Lutris or something? I guess I could buy it and find out.

Definitely don't feel like FULLY supporting a developer who pulls this nonsense, but the game looks cool, and it's on sale for $2.49, so I'll go for it. Besides, I mostly play solo anyway, so I'm not sure if I completely care.