Windows only for now. Mac is coming later. Linux, maybe. GOG, maybe. More details in the FAQ here: https://steamcommunity.com/app/2853590/discussions/0/4695658570140629717/
All great news. Reason I mention GoG is that Heroic Launcher means on Linux/Mac I can add your game and run via Wine/Crossover with a few clicks. Simple and effective.
