SoY-1: Online Tournaments "Seasons of year" - "Seasons of the Year" - Spring Season 2007

What is Hamachi? Can I play Sod 3.1 on it?

Unfortunately, you won't be able to play on version 3.1 because your opponents will be using version 4.0, but if you want, you still have time to purchase the Platinum Edition, or let me know so I can remove you from the list.
You can download the latest version of Hamachi and its description in this topic: /topic/2146/