https://www.overclock3d.net/news/software/ashes_of_the_singularity_escalation_is_available_for_free_to_humble_store_users/1
 
For the next two days, Oxide Games' Ashes of the Singularity: Escalation will be available for free to Humble Newsletter subscribers, giving PC gamers free access to the Steam version of the game. Ashes of the Singularity is an RTS game where payers can control vast armies of thousands of units, taking command of a Post-Human Coalition army to take on a new enemy called the Substrate.  Fans of PC hardware will know that Ashes of the Singularity contains strong CPU and GPU testing utilities, a factor which made the game popular amongst reviewers for several years. The game also contains a variety of multiplayer modes and a powerful, non-cheating, AI to battle against in skirmish and campaign mode. 

To redeem your copy, all you will need as a Humble account and a Humble newsletter subscription. You can create both today on Humble's website. 
 
Nothing like a FREE game!