Feel The Magic: XY/XX Codes -

Custom title screen sound:
Hold + at the title screen and record any sound into the microphone. The recorded clip will play during the introduction music. To preview it, press + at the title screen. To hear it slower, press + and to hear it faster, press + at the title screen.

Credits sounds:
Touch the Sega logo during the credits to hear the classic "Sega" sound. Touching other text and images that appear will play other sounds. After the credits and theme song ends, touch the person sleeping in the audience to hear him snore.

Opening sounds:
Touch the girl in various places at the mode selection screen and she will scream.

Bonus hairstyles:
Have one of the following Game Boy Advance in the cartridge slot along with the game to unlock a new hairstyle in Maniac mode.

Sonic Advance 1: Sonic hairstyle 
Sonic Advance 2: Sonic hairstyle 
Sonic Advance 3: Chao hairstyle 
Sonic Battle: Ulala hairstyle 
Sonic Pinball Party: NiGHTS hairstyle 
Puyo Pop: Puyo hairstyle 
Chu Chu Rocket: NiGHTS hairstyle 
Space Channel 5: Ulala's Cosmic Attack: Ulala hairstyle 

Alternately, complete the game under the hell difficulty setting to unlock all bonus hairstyles.

Body 2 and 3:
Successfully complete story mode under the normal difficulty setting.

Alternate girl costumes:
Find all the hidden rabbits

As well as collecting rabbits, go to Memories mode and play the games. For every level of a game you complete, you will get one star. They act similar to rabbits but obtained in a different way.

Girl without top:
Enter the DS system language option and change it to "Japanese". The girl on the menu screen will no longer have her top.

Alternately, complete the game under the hell difficulty setting.

Sound test:
Successfully complete story mode under the normal difficulty setting.

Hard difficulty:
Successfully complete story mode under the normal difficulty setting.

Hell difficulty:
Successfully complete story mode under the hard difficulty setting.

Birthday greeting:
The girl will greet you by saying "Happy Birthday" at the main menu on the date that you entered as your birthday in the system settings.

Holiday greetings:
Set the system date to December 25, January 1, and other holidays to hear a new greeting.

Hairstyles in Maniac mode:
Complete the indicated tasks to unlock the corresponding hairstyle.

Chao wig: Complete Hell mode. 
Lilac ponytail: Find 1 rabbit. 
Long blonde hair with blue ribbon: Find 19 rabbits. 
Long blonde hair with police Hat: Find 130 stars and 40 rabbits. 
Long blue hair: Find 49 rabbits. 
Long blue hair with cowgirl hat: Complete Hard mode. 
Long brown hair with nurse's hat: Find 100 stars and 30 rabbits. 
Long brown hair with white visor: Find 6 rabbits. 
Long gray hair with chicken hat: Find 100 stars and 35 rabbits. 
Long gray hair with red and white hat: Find 29 rabbits. 
Long gray hair with Santa hat: Complete Hard mode. 
Long gray hair with white bunny ears: Find 59 rabbits. 
Long orange hair: Find 5 rabbits. 
Long pink hair with halo: Find 182 stars and 60 rabbits. 
Long purple hair with white cap: Find 39 rabbits. 
NiGHTS wig: Complete Hell mode. 
Puyo Wig: Complete Hell mode. 
Short green hair: Find 3 rabbits. 
Sonic wig: Complete Hell mode. 
Ulala wig: Complete Hell mode. 

Costumes in Maniac mode:
Complete the indicated tasks to unlock the corresponding costume.

Angel's costume and wings: Find 182 stars and 60 rabbits. 
Blue and white dress: Find 75 stars. 
Blue and white schoolgirl uniform: Find 20 stars. 
Blue chicken outfit: Find 100 stars and 35 rabbits. 
Blue polo shirt and white skirt: Find 15 stars. 
Cheerleader uniform: Find 10 stars. 
Cowgirl outfit: Complete hard mode. 
Green and white armor: Find 170 stars and 55 rabbits. 
Green schoolgirl outfit: Find 182 stars. 
Green top and brown shorts: Find 30 stars. 
Gray and white dress: Find 100 stars. 
Nude: Complete Hell mode. 
Orange and white dress: Find 130 stars. 
Pink dress: Complete Normal mode. 
Pink top and bunny tail shorts: Find 50 stars. 
Police uniform: Find 130 stars and 40 rabbits. 
Red and white Christmas outfit: Complete Hard mode. 
Red swimming costume: Find 170 stars. 
White bikini and denim hotpants: Complete Normal mode. 
White nurse uniform: Find 100 stars and 30 rabbits. 

Shoes in Maniac mode:
Complete the indicated tasks to unlock the corresponding shoes.

Bare feet: Complete Hell mode. 
Blue knee-high boots: Find 9 rabbits. 
Brown shoes with long white socks: Find 31 rabbits. 
Cowgirl boots: Complete Hard mode. 
Green and white armored boots: Find 170 stars and 55 rabbits. 
Green elf boots: Get 51 stars. 
Purple high heel shoes: Find 7 rabbits. 
Red high heel shoes: Find 4 rabbits. 
White high heel shoes: Find 2 rabbits. 
White high heel shoes and blue leg warmers: Get 41 stars. 
White knee-high boots: Find 11 rabbits. 
White trainers: Find 21 rabbits.