IGN are offering a range of freebies to entice users to sign up for their paid subscription service, IGN Prime. Included in said range of freebies are some free games or beta keys (including a Steam key for Rochard) and, far more excitingly, a code for GamersGate that lets you get 15% off any and all purchases from GamersGate, for life, including special offers.
You can register for a 7 day trial for IGN prime (and you’ll need to give them payment details) redeem the code on GamersGate, and then immediately cancel your IGN Prime membership (turn off autorenew, and you’ll never get charged), and GamersGate will still honour the 15% discount. It’s a bit of a steal, hop to it. I’m not sure how long this offer will be available for.