This free "game" lets you program virtual robots to battle each other, against friend's robots, or in a worldwide arena. Note that it's really pretty educational in addition to being fun!

For years, I've toyed with virtual robot battle games. Usually, these are called p-robots (pascal), c-robots (C), and use a text based simulation engine which just prints the names of the robots that won each virtual battle. These are a great way to practice your logical thinking and touch-up on your programming skills, but ultimately, they weren't very interesting to watch.

Robot Battle is a free program which takes the educational aspects of the older programs and bolts-on a nice graphical interface to depict the battles. This lets you watch your robot's behavior and aids in debugging and improving the algorithm. Robot Battle uses a simple, custom programming language, so it won't teach you an actual language's syntax, but it will let you hone your abilities to create logical operations and solve problems.

You can submit your robot into a world-wide massive competition or share ideas and code via the community forums. This tool is useful for everyone from rank beginners to seasoned programmers looking to have a little creative fun. You can get Robot Battle directly from the developer.