All the data is on little strips of dots.. (I'm guessing that they're zeros / ones.) That's the programming for the game. The E-Reader takes all of the information, puts it in order, and executes the "Application".

It's just like any other program.. And I bet that if you could "decode the codes" somehow, you could program your own games onto your own cards. Just looking at the lines of code, though, it would be nearly impossible, given just how tiny those dots are and their proximity to each other....