While I am still in the process of figuring out the system's nuances, it is fairly easy to jump into the "game" and get to work on a simple game. Kodu
comes with a path and terrain editor, 20 different characters and the ability to implement 4-player co-op gameplay. Though not currently available, Kodu
will eventually allow players to share their creations with friends.
Though geared towards younger players, Kodu is accessible to anyone willing to learn. The included tutorials leave something to be desired, but the toolset is easy to understand and is a great introduction to logic and problem solving. Coming from someone who has been running game camps for five years, I've found systems like this are a great introduction to what programming entails.
Check out the following video for an idea of what Kodu can do.