Secret Base Zone is the second zone in Sonic Advance. The zone is made up of zip lines, moving and bouncy platforms, and melted metal. At the end of act 2, Sonic battles Eggman in a pogo-like Egg Mobile. It will bounce around trying to hit you until it is almost defeated. Then it will jump off screen and will land were ever you are. If you do dodge it you must also jump to avoid taking damage from the shaking ground. It will then bounce around again and off screen every once in a while till defeated.