Northgard is a strategy game based on Norse mythology in which you control a clan of Vikings vying for the control of a mysterious newfound continent.
After purchase it is necessary:
1. Download and install Steam http://steampowered.com/download/SteamInstall.msi (if not)
2. Register a new account on Steam or go to an existing one;
3. Select "Activate via Steam ..." in the "Games" section
4. Enter the code you received after payment.
5. After activation, the game appears in the list of games and you can download it from steam, and then start playing.