Enter these codes during a level, the best spot is usually the beginning of the level, these codes can be fond out by obtaining all 5 stars at the end of the level and the camera and marshmallow codes can be put in, infinitely. Also, you must these codes in fast because doing it slow will not work.
A camera
Down, Up, Right, Right, and Select and B at the same time.
A marshmallow
Down, Down, Left, Left, and Select and A at the same time.
Full Health Restore
B, B, Select and X at the same time, A and R at the same time, and Select.
Halfway Health Restore
A, A, Select and A at the same time, Down, Down, and Down.
Halfway Special Attack Gauge
Down, Down, Left, Right, and Select and X at the same time.
Invincibility
Select and A at the same time, Up, Select and R at the sametime, Down, and Up.
