Does anybody know, if this version is either compatible with Holiday scenario or if it even includes it?

As the Steam version does not and certainly is not compatible with it, not without some very serious tinkering, which not always even works.

Well, AFAIK, there is a mod available: that includes the Christmas map. People have managed to get it working on the Steam version as of 2016 on Windawz 10, but with some special tweaks: [url=]https://steamcommunity.com/app/7600/discussions/0/154641879451131960/.

In case anyone is still interested, the GOG version does work with the Holiday Scenario as well as Mange's Tender Mod, I have it all running on a Surface Book with no problems. The GOG version does not include the Holiday Scenario, and I did have to do some minor tweaking of file locations to get it working with the tender mod, but it is all working great.