Secret Level
     Walk  behind  the  big  statue  in  the Museum Level. It will say
"02P". That means when you get your power level at 02, push the statue
and you will fall into a secret level.

Unlimited Extra Lives
     In  the  beginning  of the game, get the extra life on top of the
fountain.  Then pause the game and check your status. Unpause the game
and  you  will  see  the extra life is there again. You can keep doing
this to get as much lives as you want.