Successfully complete the game. Then, return to the Bottle Ship after the credits end, and the locations of all items will now appear on the map. Additionally, you can see your percentage of collected items.

Successfully complete the game with 100% item completion to unlock the Hard difficulty.

Successfully complete the game to unlock the "Gallery" option at the main menu. Successfully complete the indicated tasks to unlock pages in the Gallery:

Pages 1 to 4: Defeat the final Story mode Boss.
Pages 5 to 7: Successfully complete the game.
Page 8: Successfully complete the game with 100% items.

Successfully complete the game to unlock the "Theater" option at the main menu. Successfully complete the indicated tasks to unlock chapters in the Theater:

Chapters 1 to 26: Defeat the final Story mode Boss.
Chapters 27 to 30: Successfully complete the game.

Defeat Phantoon and unlock the hidden ending to change the title screen music.

Charge your Beam and turn into the Morph Ball before releasing it to drop five normal bombs at the same time.

Charge while in Morph Ball form to be able to immediately shoot a Charged Beam when you turn back into Suit form.