http://www.zeldaclassic.armageddongames.net/viewquest.php?q=271
which is Metroid Legends
here are the 2 cheats I know for Metroid Legends
Level 1: samus
Level 2: ridley
not sure (yet) about Level 3: and also Level 4: (but if you know one or both of them please post them, thank you if done or not).