It's Father's Day this weekend! And what better way to celebrate Dad than giving him a giant tool. To hammer Orks with.
Relic's third-person ground pound simulator, which is still mightily entertaining seven years after release, is being made available for free through Humble Bundle over the next day and a half. There is a catch - you'll have to sign up to their newsletter, but once you've signed up you'll be emailed the key straight away, and then you can stay subscribe or unsubscribe from the newsletter afterwards. Easy.
As far as "I want to turn my brain off and just carve through a bunch of things" video games go, Space Marine is still plenty of fun. Duck on over to Humble Bundle to get your Dad (or yourself) a key now. Just note that you'll need to redeem it into your Steam account in the next 30 or so hours; the keys will expire if you haven't redeemed them by then.