We have one million SpaceChem Steam keys to give away, with Bundle Stars

SpaceChem is a puzzle game about building factories to create increasingly complex molecules.

Our next giveaway, for Dino D-Day, is live here.

SpaceChem is a puzzle game about building factories to create increasingly complex molecules. It's clever, absorbing, and a great way to test your logical reasoning power. We enjoyed its cerebral charms so much it earned a score of 89 in our review. Now we're teaming up with Bundle Starsto give you SpaceChem for free. We have a million copies to give away, so don't be shy, click through to grab your Steam key.

SpaceChem is just the start of a huge five-part giveaway we're running on PCGamer.com in the coming weeks. We're giving away millions of Steam keys, so keep an eye on the site for the latest offer every Wednesday. As mentioned, this is all in association with Bundle Stars. As well as selling games independently, they specialise in bundling them together to create deals that discount games by up to 97%. This giveaway is your opportunity to build a free Steam bundle over five weeks. To begin, Follow the instructions in the form below to claim your SpaceChem Steam key.

Here's a video of SpaceChem, which should explain things nicely while you wait for the game to install.

A total of 1,000,000 Steam keys are available for SpaceChem, which must be claimed by 17:00 GMT on 2 July 2014. The offer is open to owners of eligible Steam accounts. By taking part in this giveaway you agree to be bound by these terms and conditions and the further rules which can be viewed at www.futuretcs.com.

This promotion is managed by Bundle Stars, a division of Focus Multimedia Limited. Future Publishing Limited are not responsible for the Steam keys relating to SpaceChem. Contact Bundle Stars directly by emailing support@bundlestars.comif you have any questions or concerns about entering your key or downloading the game.