At the title screen, press: X, B, Y, A, A, A, A. If entered correctly, you will hear a voice saying: "Easy Game". When playing the game now, your weapons will charge fast !
Fast Weapon Recharge
At the Title screen, press X, B, Y, A, X, B, Y, A, X, B, Y, A, X, B, Y.
Unlock Hyper Laser
Complete the game on Normal difficulty to unlock the Hyper Laser.
Unlock Spread Rocket
Complete the game on Easy difficulty to unlock the Spread Rocket.