Where is the complete order now part where you download a game?

I want to down load this game, went to the check out but it says that if I click 'complete order now' it will take me to where I can pay and then download the game but I cannot see anywhere on the page where I can click 'complete order now'

If the game is in your shopping cart (the little symbol in the top row of the site), you can click on it and an option called "checkout now" should appear. That will take you to the checkout screen, where you can choose your payment method and complete the order. Afterwards, the game will appear in your library (click on ACCOUNT in the top row) for download.