Cloudball is a fun and challenging programming competition developed by Giraff (www.giraff.se) in cooperation with Microsoft.

The goal is to develop your team so it can handle different tactics from all other teams. To win the competition you probably need to stretch your skills in programming.

See: http://cloudball.wikia.com

You need MXA Game Studio (Microsoft XNA Game Studio).

You can get that on CodePlex: https://mxa.codeplex.com