The hack-and-slash action game Killer is Dead is free for a limited time through the Humble Store.
The game normally costs 19.99 euro but for the next 48 hours you can get it for free from the Humble Store.
To get the game, just go to the Killer is Dead: Nightmare Edition page on the Humble Store, and click "Add to cart" then "Checkout". After that click "Get it for free." Once you get the game, it will be yours forever.
But be careful, because the keys cannot be redeemed after December 2.