Games as recruiting tools aren't anything new, but this little free browser game was more entertaining to me than America's Army ever was. The point of the game is to emphasise how important teamwork is (and how you can learn it in the military), so it matches you up with three other players and gives you a series of puzzles to solve.
The catch is that when you fail or succeed, your teammates are penalised or rewarded. Your goal is to last as long as possible as a team.
At the end, you're graded against other people's times, and on various factors like multitasking and concentration. Turns out both of those drop pretty sharply when you're trying to explain how a game works while playing it.
You can play the game for yourself here.