My boys play this for hours. The learn to sit up straight (oops, I'm severely slouching right now), keep their feet on the floor and their fingers on home row. They practice a series of letters and spaces and then they get to play the "shooting bugs" game. I've found it universally exciting for both boys and girls. They learn to type letters first (in a specific sequence of home row first followed by keys that involve reaching). After they've mastered the letters (it keeps track of accuracy and they can't move on until they get a certain percent correct) they get to move onto higher and higher levels, typing words and then even paragraphs.
I find it's an awesome game that CJ pulls up during his independent study time. He's practicing the basics of reading and learning exciting new computer skills at the same time.