Hi Renee, thanks, sorry you had problems, the easter eggs are only there to show that you need to do something to view the extra content it is not as simple as clicking on the easter egg (that will not work).
If you can not complete a section click on the master icon and he will show you a video of how to complete the level. As a hint for the find the coin level look at the picture and the safe.
The navigation was intentional and the aim was to get the user to explore., and with no ability to go backwards to give a real world feel to it, I did toy with different navigation elements during the design, you can try each game as many times as you like and there is no need to view the introduction again.
It depends on which shuriken game you played (there are two in there) but the key press one could be used to ask questions under a time limit (where you press a,b,c) or it could be used for learning to type or even to fill in the missing letter for learning to type. The other game is just a bit of fun.
I did look into the pause button, but didn't implement it for a couple of reasons the introduction is short and pauses on each slide and the games rely on a timer element that pausing may help you complete some of the task.