Activities in this are all very simple by design so as to be easily completed by a child who had never seen a keyboard or mouse before, while also being fun enough to keep the attention of kids that have mastered these skills. Many of them are not passive, instead actively reacting to user inputs that experienced users tend to not think about. Something like mouse movements which normally only produces subtle rollover affects needed to provide very high energy and exaggerated feedback in these activities.
To help teach click and drag (drag and drop) functionality we decided that a tried and true puzzle is still an excellent way to introduce the concept. The puzzles, though simple, begin in their completed state before the pieces scatter. There is a lot of tolerance given to acceptable drops and pieces will drift into place. These and all activities have timers to progress after a fixed amount of time in case of idle or struggling users.
As a way to practice clicking and as a game to reward sitting through the lesson we created this balloon popping interface. The student has 30 seconds to click on as many balloons as possible. This actually became so popular around the office that a number of developers spent several days competing to see who could pop the most. It is so fun that it's the only activity that plays twice.
