Metroid Samus Return’s Japanese website has revealed exactly what we can expect the new Metroid Amiibo to unlock in the game.
The unlocks include an art gallery, FUSION difficulty mode, concept art gallery and a sound test as well as a variety of in-game abilities.
It’s unclear at this stage whether the only way to unlock these are to use the mentioned Amiibo. There’s a suggestion in the Japanese text that makes us think that you might be able to also unlock it by beating the game (or potentially beating the game AND owning the Amiibo).
The Amiibo functionality can be found below:
Samus Aran (Metroid Series)
Elon Reserve Tank (special ability recovery)
Metroid II Art Gallery (unlocked after beating game)
Metroid (Metroid Series)
Metroid Marker (tells you location of nearest Metroid)
FUSION Difficulty Mode (unlocked after beating game)