To win on Super Power island, you have to recapture all 6 of the escaped super-villains and return them to prison. After you catch the first 5 using your wits alone, you receive super flying power to chase the 6th, Betty Jetty.
(see related question for full solution)
you beat all the villians
You do get a medallion, you just have to defeat all of the super-villains first.
The island after Super Power Island was Spy Island.
No, there is no "super strength" on super power island glad to help :D
The subway is Downtown on Super Power Island.
There are no cheats in super power Island.
Go as far as you can to your right in Super Power Island.
Yes, that is how I completed super power island!
you can't get speed on super power island
There are 6 villains to defeat on Super Power Island.
The force shield is not an item on Super Power Island
Hide in the screen you'll win pinky promise