Although it was only released yesterday in the West, plenty of Star Fox Zero secrets have found their way online in the form of videos–yeah the internet works fast. One such video can be found below, which quickly discusses the unlockables featured in the game. Because the annotations are difficult to follow, I’ve also included a list of each unlockable and how they’re acquired. But for the sake of spoil-free posting, I’ll put it all past the break.
Retro Arwing: Tap the Fox amiibo or Collect 70 medals in the story missions
Black Arwing: Tap the Falco amiibo or Collect 70 medals in the story missions
Arcade Mode: Complete the main game. This mode starts the player with one life, and forces player to continue through their chosen route with no map overview
Sound Test Mode: Complete Arcade Mode
All Challenges: Collect enough gold medals: 5 for the Walker, 15 for the Gyrowing, 30 for the Landmaster, and 50 for the Roadmaster (Mission #2)