I bought the game on GOG and I am pretty disappointed at how the developer handles patching for customers who didn't buy the game on steam. Recently they released a new patch on 6 Aug and this patch is only available to players on steam. It is not even on their website so you can't do the patching manually either. So far they haven't announced anything about this patch on GOG and they don't check the comments on the GOG forum. I had to ask them on the Steam forum to get a reply that the patch was delayed because of a bug(they said the bug was fixed on 13 Aug but we still haven't got the patch on GOG yet). And this is not the first time problems like this happened. If you read the message on http://steamcommunity.com/app/243970/discussions/0/617336568083751234, last time they even forgot they had to release the patch on GOG. Note that I am not saying this game is bad or this developer is a bad company. I actually think they did a good job of updating the game post release, adding new content, making balance changes according to feedback and answering fans' questions on the steam platform. But if you are paying the same price for this game, there is no reason for you to buy this game on GOG.