Pause the game and enter L, A, Left, L, Right, Down, Down. Unpause and use the Y button to float around the current level
It's "LAWLESS" using:
(N)orth = up (E)ast = right
(W)est = left (S)outh = down
Pause the game and enter R, Right, A, L, Right, A, Down, Y.
It's "REAL EASY" using the following guide:
(N)orth = up (E)ast = right
(W)est = left (S)outh = down
Pause the game and enter L, A, Z, Y, Left, Right, A, Down, Right, L.
It's "LAZY WEASEL" using:
(N)orth = up (E)ast = right
(W)est = left (S)outh = down