Astro Boy: The Video Game Level select
Pause the game and press Up, 1, Right, 1, Down, 1 to unlock all levels.
Invincibility
Pause the game and press Up, Down two times, Up, 1, 2.
Max stats
Pause the game and press Left two times, 2, Down, Down, 1.
Infinite Dashes
Pause the game and press 2 two times, 1, 2, Left, Up.
Infinite Supers
Pause the game and press Left, 1, Right, 1, Up, Down.
Disable Supers
Pause the game and press 1 two times, 2 two times, 1, Left.
Alternate costume
Pause the game and press 2, Up, 1, Up, Down, 2.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art / Original