Here you have our pre-order page. The game will be available with a 15% off until Early Access launch, next 8th of October:
http://www.ballistic.com/preorder/
Remember that with the code you will be able to activate the game on Steam, but you won't be able to install and play it until 8th of October.
Preorder Ballistic Overkill. Click on the following image to access our Youtube channel and learn more about Ballistic Overkill.