Nemesis Cheats (GameBoy)

Start the game, then pause it by pressing Start. Now press the A Button, then Left four
times, then repeat the sequence four more times. Use this code only if you want a real
challenge; it will take away all your ship's accessories!

Start the game, then pause it by pressing Start. Now, press B 5 Times, then A 5 Times.
This will work once per game.

Pause game play and press Up, Select, Down, Select, Left, Select, Right, Select(3).
Collecting power-ups will have no effect on your ship.

Start the game, then pause it by pressing Start. Press Up, Select, Down, Select, Left,
Select, Right, and Select, then repeat this sequence twice more. Use this code only for
added challenge; it prevents you from powering up your ship!

Start the game, then pause it by pressing Start. Now press Up, Up, Down, Down, Left,
Right, Left, Right, B, A and Start.

Level 2
  Destroy the volcano towards the top after the ceiling drops and rises. Fly through the
hole where the volcano was located. 
  Level 4
  Destroy the second Re-Bone blocking the narrow passage near the end of the level. Fly
to the bottom of the passage to reach the wall behind your ship.