Its simple and colorful graphics give it a particular charm and make it very attractive for children, who can learn almost without realizing it.
You can choose to start on any of the levels/lessons straight away, and then learn at your own pace meaning you cannot win or lose. A series of letters fall from the top of the screen and you must press the corresponding keys in the correct order and time while the scoreboard records your success or failure. The player can then keep trying to better their score until they perfect the level.
So if you want to move from prehistory to the present age (as represented in the design of each level) you just have to complete each level and convert yourself into a professional typist.