At the Options screen press Down A Down Y down A Down Y. Start a game and pause the game when Aero appears. Press Up X Down B Left Y Right A L R. Then pause gameplay again and press Select. Now hold R while the bonus points are calculated at the end of any level.
Full Level Select Menu
First enter the code above then at the Level Select screen press L R X B Left Up Right Down Y A.
At the Full Level Select Menu press A Y L Up Down R A Y Right Left.
No Enemy Collision
At the Full Level Select Menu press Down A Y R Y B Up L Y A.
At the Title picture with Aero flying press X Y B A X A B Y Up L.
At the Title picture with Aero flying press X Y B A X A B Y Up R.