All weapons:
Press Left, Right, Up, Down at the title screen. Then hold Z and press Right, Right, Left, Left.

Level select:
Hold Z and press Right, Down, Down, Right at the title screen. Release Z, then press Right, Up, Down, Left, Left, Up, Right, Right.

Invincibility:
At the title screen, hold Z and press R, R, L, L, Up, Down, Left, Right

Easy Way to Destroy Bees:
Here is an easy way to destroy bees: Wait to hear the buzzing sound that notifies you of their arrival. Then wait for them to get very, very close to you (when they lower their altitude to hit you). Use your weapon with star-type ammo to shoot them. You will hit them 99.9% of the time. If you shoot them and they hit you, you will not lose as much health as normal.

Play as Dark Stinger:
While the game is loading hold Z and UP on the joystick. Then press C-Up, C-Right, C-Down, C-Left 5 times. Next press B, A, B

Refill Life and Ammo:
While playing press A + B + R to restore your health and ammo.

Infinite Lives:
At the title screen press L, R, B, A, Z, Left, Right

Fast Forward Text:
When text appears press Z to fast-forward or A to skip it entirely.

Level 6 Gun:
On level 6 pick up the nuclear device then while carrying the device, fly towards the mountains to a steel like drum. Fly over the drum and you will get a special gun

How to Kill The Evil Heard Queen:
To kill the queen just fly real high and shoot her in the head,she has another body! To kill it shot in the head then run if not you'll get killed so keep repeating and you'll beat the queen!

Easier Destroying Enemys:
Instead of using the normal laser beam as your primary weapon, try using the Plasma Cannon as your primary weapon. This way, most basic enemys will fall down with just one shot of the gun!