Its easy(you have to have unlocked mario and the power flower) . Go to the room that you got Luigi in(upstairs, the last room on the right) goto the end of the room. There is a red coin there but dont fall down the hole.Go in the door and you will see a ! block. use it to float across the room and get the red coin.
On what level?
enter the 32 Star-Coin door to toggle between Mario and luigi
in your neck
Yes
It is down a tube so don't destroy them all as big Mario
super Mario sunshine
On what level?
In Soviet Russia, coin gets you!
enter the 32 Star-Coin door to toggle between Mario and luigi
in your neck
Yes
youtube chuggaconroy
It is down a tube so don't destroy them all as big Mario
By getting every single Star coin
Collect 100 coins in that mission
knock down all of the star coin signs
The Super Mario Bros- Super Show - 1989 Game Show Host The Great Gold Coin Rush 1-47 was released on: USA: 7 November 1989