Custom title screen sound:
Hold Down + Y at the title screen and record any sound into the microphone. The recorded clip will play during the introduction music. To preview it, press Down + X at the title screen. To hear it slower, press Down/Left + X and to hear it faster, press Down/Right + X at the title screen.
Classic Sega sound:
Touch the Sega logo during the credits to hear the classic "Sega" sound.
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.
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.
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.
