MUST READ. THIS CD-KEY MUST BE REDEEMED BY MAY 5TH 2018 AT 10:00 AM. IT WAS A FREE KEY FROM THE HUMBLE BUNDLE STORE. I ALREADY OWN THIS GAME AND JUST WANTED TO PASS IT FORWARD TO SOMEONE WHO MAY NOT HAVE IT. DO NOT COMPLAIN IF YOU WAIT TOO LONG TO REDEEM THE KEY AND IT IS INVALID. I WILL SEND THE KEY WITHIN 1 HOUR OF THE GIVEAWAY ENDING.

From the Humble Bundle key page of mine:
"The redemption deadline is May 5th, 2018 at 10:00 AM Pacific. You have 1 days left!

Immediately after 10AM Pacific on May 5th, the Steam key will magically vanish as if it were just a figment of your imagination, leaving this cryptic message behind in its wake."