From today, the game has removed the DRM, that is include Steam DRM (Im do forgot to change the version date to today).
There is something to remember:
1. If you want to support me, purchase the game and/or the DLC directly here on steam and only on steam!
2. Im do not get any payment from any keysellers at all, but im will also do NOT deactivate any keys of those.
3. Now im also have removed the DRM as the game is now a quite old.....