Milo arrives on Earth to find that he's way too small, everybody's gone and a day hasn't passed sinc..

Tinykin

Milo arrives on Earth to find that he's way too small, everybody's gone and a day hasn't passed since 1991! Team up with the mysterious tinykin and use their unique powers to create ladders, bridges, explosions and a lot more! Find a way home through a sprawling ant-sized metropolis, and unravel Earth's biggest mystery!

Explore cities of ants, beetles and other insects built inside of a giant house
Meet characters everywhere you go and learn their stories and history
Catch over a hundred tinykin in each city, and use their special abilities to climb higher, break down doors and solve the city's problems!
Skateboard around on Milo's tiny soap-board! Jump, grind and hover around the house
Collect upgrades to improve Milo's bubble-pack, build out the Ardwin Museum and complete Ridmi's mysterious machine!

Minimum Requirements:

OS: Microsoft® Windows® 7 / 8 / 10 64 Bit
Memory: 2 GB RAM
Storage: 2 GB available space
Sound Card: DirectX compatible

To activate the Steam key you've received, follow the instructions below;

First up, open the Steam client. (If you don't have it, simply click the "Install Steam" button here => Steam Store )
Sign in to your Steam account. (If you don't have one, click here to create a new one => Steam Account)
Click on the "ADD A GAME" button in the bottom corner of the client.
Then, select "Activate a product on Steam..."
Write down or copy-paste the activation key that you've received from GamesForPlay in the window.
Your game is now visible in your library! Click on your "Library".
And finally, click on the game and select "Install" to start your download.