Pilotwings 64 Cheats (Nintendo 64)

In the "little states" level, use the "gyrocopter"
  and hit the "mario" face in "mount rushmore" it''ll turn in too "wario''s" face.

On each island of Pilotwings a yellow star is hidden. When you touch this star you will
appear as BIRDMAN.
  To get to a star easily, get the ROCKET BELT in all levels. Here are the locations of
the stars:

When you are in the Little States, fly to the south east part of America (Georgia). You
will find an intersection with gas stations at all corners, fly in-between the pumps and
station and you will be filled up 'free'. It won't help you with any challenges, but will
help when you are exploring.

Fly straight ahead until you reach the coast at the other side of the castle. Somewhere
there is a rock with a bend in the sea. Underneath it, there is a star.

Go to New York with the statue of liberty. In the central there is a little park and here
you will find another star.

Choose test 1 and fly ahead and cross right towards the waterfalls. In the top of one of
the falls, there is a secret entrance. When you follow this entrance you will bump into a
star.

Choose test 1 and turn 45 degrees to the left. Fly low above the village. When you past
the village, watch the big cave along the coast. In it, there is another star.