Quick! Surviving Mars is free to keep for the next few hours

This is a PSA to all you fans of city-building sims: Surviving Mars is free to keep on Steam right now, and you have until the end of the day to grab it. To be fair, Surviving Mars is less a "city" builder and more a colony builder, where it's your job to set up a home on the little red planet for humans to populate. It's a good time too, we reckon it's one of the best management games and best building games on PC, so you might as well take this opportunity to add it to your library.