Having just released a brand new trailer for Metro: Last Light, THQ apparently thought it might be prudent to drum up excitement for the sequel in the best way possible: by giving away its predecessor for free.

Just head over to THQ's official Metro Facebook page and press the 'Like' button, then follow the on-screen instructions to download your complimentary copy of the phenomenally atmospheric Metro 2033.

It seems the codes may be limited, so get one while you can. If you haven't played Metro 2033, you'll be delighted by how scary and tense it is. If you have, let us know what you want out of the sequel.