https://www.humblebundle.com/store/the-red-solstice
Free for 48 hours -enjoy
(Free key is available for 48 hours, redeem on Steam game is yours forever)
Key redemption deadline is January 31st, 2018 at 10:00 AM Pacific.
"Immediately after 10AM Pacific on January 31st, the Steam key will magically vanish as if it were just a figment of your imagination, leaving this cryptic message behind in its wake."