It has DRM

The game is really good. But it has DRM. Remember what GOG says: "DRM-free means no copy protection, on-line checks, or any other annoyances. It’s all about just you and your games and movies. You should feel you own the products that you buy - just like a book, or a DVD." This game has online check. You can't play at LAN without internet connection, you can't play at LAN if you have not 2 or more copies from the same game, you can't play multiplayer at home with your family without 2 or more copies... Beware before buying this great game.