I have tried everything, including restarting and taking the cartridge out. I know youre supposed to shoot the square on top of the door, but it just wont work. I have tried all beams, powerbombs, and everything possible, but the door wont open.
Shoot it from the other side, those are there too be one way areas. If you have the power bomb ability go back to the beginning of Norfair and use the power bomb in opening room of the area where you got the freeze gun. If your just starting look for the speed boosters keep following the path you were on before getting to that metal door before coming out in a green area. Go upwards and look for a place to blow a hole open in the cealing for the speed boosters which you then use to get the ice gun.