Autumn is coming. Leaves fall, and spirits rise from the fallen leaves to begin their journey home. You must guide them, without direct control, by changing how the wind blows or by rebuilding the ground. Each spirit can be sacrificed to perform one of four actions – build a bridge of leaves, create a blowing cloud, dig tunnels, or block wind currents in an area. Use your actions wisely or you will run out of spirits. In each level it's up to you to find your own creative solution on how to get the spirits to the goal.Go to: http://store.steampowered.com/ and download STEAM client
Click “Install Steam” (from the upper right corner)
Install and start application, login with your Account name and Password (create one if you don’t have).
Please follow these instructions to activate a new retail purchase on Steam:
Launch Steam and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam…
Follow the onscreen instructions to complete the process.
After successful code verification go to the “MY GAMES” tab and start downloading.