Atmospheric FPS Metro 2033 can be yours at no cost if you head over to Facebook and like THQ's page.

You'll be promoting the new Metro: Last Light game to your friends by doing so, with the free game download being your reward.

Once you've liked the page you'll be sent a code - while supplies last - which can be redeemed on Steam.

Alternatively you can snap up the rather great Humble THQ Bundle, which includes Metro 2033 and a host of other games.

Source: Facebook