dude 4 green star number 3 u will c a ! box butt dont go in it instead tap the cymblye with the bowser face on and a challenge room will appear kill the enemy and green star 3 is yours and the stamp is located outside 2 get it make sure u have a propeller box after the check point then when u get back inside after five keys u will c some enemys that throw spike follow it & it will lead outside fly