Nice addition for perfect game! At the beginning I was sceptical about this one, but after playing it I must admit they polished many game features. Regarding other reviews, I don't know where this "no DRM-free" propaganda is coming from, because there is no DRM in this game. Yes, there is Log-In panel after starting the game, but there is also option "Log-In as guest" at the bottom. Running game in guest mode does not limit you as player in any features game offers.
