It was only a few weeks ago that the Humble Store most recently gave away a game for free, specifically the PC version of GRID, to spread some holiday cheer to gamers around the world. Now, another Codemasters title is now yours to grab at no cost.
DiRT Showdown, was first released for Microsoft Windows in May 2012 and eventually for macOS X and Linux in more recent years. While not as popular as GRID, DiRT Showdown for PC still managed to obtain a Metacritic score of 72%. While the console versions of the game are not included as part of the Humble Store giveaway, most people should still be covered by one of the aforementioned operating systems.
As is the case with Humble Store purchases, you'll need to head on over to the website and click on the 'Get it Free!' button. You'll need to log in with your Humble account credentials (or go through the process to create one) before completing the transaction.
Once checkout process has been completed, you can click through to obtain your free Steam key which you can then instantly redeem via the Steam client. However, you'll need to get moving as soon as possible as the offer to obtain a free DiRT Showdown key remains available for the next 18 hours only. Furthermore, all keys must be redeemed by 10:00 AM Pacific on Saturday, January 28th, 2017 otherwise they will disappear from your Humble Store account.
Source: Humble Store