Custom title screen sound
At the title screen, hold Down Y 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.
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.
Set the system date to December 25, January 1, and other holidays to hear a new greeting.
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, successfully complete the game on the hell difficulty setting.
Touch the girl in various places at the mode selection screen and she will scream.
During the credits, touch the Sega logo to hear the classic "Sega" sound. Touch the other text and images that appear to hear other sounds. After the credits and theme song ends, touch the person sleeping in the audience to hear him snore.
Alternate girl costumes
Find all the hidden rabbits to change the girl costumes.
Body 2 and 3
Successfully complete story mode on the normal difficulty setting to unlock Body 2 and 3.
Successfully complete story mode on the normal difficulty setting to unlock the sound test option.
Successfully complete story mode on the normal difficulty setting to unlock the hard difficulty setting.
Successfully complete story mode on the hard difficulty setting to unlock the hell difficulty setting.
Have one of the following Game Boy Advance games in the cartridge slot to unlock a new hairstyle in Maniac mode:
Chu Chu Rocket: NiGHTS hairstyle
Puyo Pop: Puyo hairstyle
Sonic Advance 1: Sonic hairstyle
Sonic Advance 2: Sonic hairstyle
Sonic Advance 3: Chao hairstyle
Sonic Battle: Ulala hairstyle
Sonic Pinball Party: NiGHTS hairstyle
Space Channel 5: Ulala's Cosmic Attack.
Alternately, successfully complete the game on the hell difficulty setting to unlock all bonus hairstyles.
Look on the top screen to see which lane the person is flying down. Then, pay close attention and firmly stroke a straight line down the path the man in the cart will soon come through. Every spike-ball will move just enough for the cart to get by. This level is otherwise nearly impossible to complete.
Defeat Plants Boss
Go to the right-hand or left-hand corner of the level and remain there patiently. Eventually a vine will come down inches away from you, but not quite hitting you. Just burn it and go back to the corner. Needless to say, you should be as close to it as possible. The vines cannot hit you if you are tucked in a corner well enough. Eventually you will begin throwing your stakes of fire into the creature's mouth. As for this part, do them one at a time if needed. It is better than losing one third of your health just from hitting his teeth once.