As sad as I feel writing this, GOG is an afterthought for the dev. Game has massive issues keeping track of achievement and unlocks progress, but only on this platform. Works on Steam just fine. Also read the Steam version has map editor while this one doesn't (did not confirm though). In general I love the concept of the game, it's amazing. It's also the best coop RTS you could find atm via the generated campaigns that is the conquest mode (can also be played solo). Objectives and map rules are varied and very interesting. But I got tired of all the technical issues so I stopped playing (went through several conquests with a friend). You can't even save/load - well, technically you can, but when you load, my friend always disconnects, so it's unusable.