- Original Japanese voice acting
Successfully complete the game, then choose to begin a new game. Then at the difficulty selection screen, keep pushed L + R and press Left, Up, Right, Down, Left, Up, Right, Down, Left, Up, Right, Down. If you entered the code correctly, you will hear a sound.

- Completion bonuses
Successfully complete the game on the Normal difficulty setting to unlock the Hard difficulty setting. You may also begin a new game to access a bonus sub-quest and have all previously unlocked costumes, money, and the drill power-up available. Although you will have to find the Headgear again, they will be at their previous levels.


Successfully complete game on the Beginner, Normal, Hard, and Happy difficulty settings. Begin new game and get the drill then return to town. You can find Popon in front of Fan's cake shop. Talk to her and you will be able to play as her.


Successfully complete game on the Beginner, Normal, Hard, and Happy difficulty settings. Begin a new game and go to the final locked house in human town and enter 'LEGENDARY' as a password to unlock Boss Rush mode. Notice: Enter 'yarushikanaiwane' as a password in the Japanese version in Hiragana/Katakana. Boss Rush mode allows all eight Bosses to be fought in succession.

- Alternate costumes
Successfully complete the indicated task to unlock the corresponding alternate costume. Use the dresser in the corner of Parin's room to change costumes.

Santa Outfit	Set the system date between December 25th and 31st.
Swimsuit	Successfully complete Boss Rush in Crazy mode.
Pajamas	Get the good ending in Normal mode.
Chinese Dress	Get the good ending in Hard mode.
Monkey Suite	Get the good ending in Beginner mode.
Work Uniform	Successfully complete Boss Rush mode in Hard mode.
Leopard Suit	Get the good ending in Crazy mode.
Maid Outfit	Can be bought from the vending machine at Spinach Caverns - Shadow Grotto.
Samurai Outfit	Give 30 Gold Medals to Hyperbolic in Crazy mode.
Nurse Outfit	Successfully complete Boss Rush mode in Happy mode.
Kimono	Set the system date between January 1st and 7th.
Armor	Give 30 Gold Medals to Hyperbolic in Beginner mode.
Vampire Outfit	Give 30 Gold Medals to Hyperbolic in Hard mode.
Princess Dress	Give 30 Gold Medals to Hyperbolic in Normal mode.
Witch Outfit	Give 30 Gold Medals to Hyperbolic in Happy mode.
School Uniform	Get the good ending in Happy mode.
Workout Gear	Successfully complete Boss Rush mode in Beginner or Normal mode.

- Movie Watcher
Successfully complete Boss Rush mode to unlock the 'Movie Watcher' option.