Play "Lost in Labyrinth" and find the treasure. You can walk through the virtual labyrinth by pressing one of the four push buttons. Doing so you will enter a new chamber. Red LEDs indicate the walls of the actual chamber. You found the treasure when the yellow LED flashes.
The circuit is powered by a PICAXE 18M+ microcontroller.
Have a look at the video to see how it works.
And don't get lost in the labyrinth.