When you get to the screen that flashes 'Start' press and hold diagonal Up/Left X Square then press Start. When you start the game you will have more time to finish the level and the enemies will be weaker.
Finish the game in less than 2 hours and leave your memory card inside slot one. At the title screen press the Start button. During the game press and hold L2 and R2 on controller two. Next press the X button on controller one. This should activate the Flight Mode. The Flight Mode allows you to use the R2 and l2 buttons to fly up and down. Reenter the code to return to normal.
Special Menu Options
Finish the game in less than 2 hours and leave your memory card inside slot one. When you get to the title screen press the start button. A new option should appear called Special.
When you get to the Start screen quickly press L1 R1 L2 R2 Square X Triangle Circle. When the game starts there will be more enemies and less powerups.