You must enter these codes at the Title Screen.

Code	Effect
B, Right, A, Down, Right, Up, B, Left, A, Up, Right, A	Allows you to choose which level to start on. Use Up and Down to select.
Down, A(x26) Down	Atari Pitfall
C, Right, Down, C, Right, Down, C, Right, Down	Displays the credits
B, A, Right, C, Right, Up, Down	Gives Harry super speed.
C, C, C, C, Left, A, Down, Up, Down	Gives Harry unlimited continues
Left, A, Down, B, Right, A, B, Up, Down, A, B, Up, C, A, C, A	Gives you extra weapons and lives at the beginning of the game.
Right, A, Down, B, Right, A, B, Up, Down	Grants Harry 9 lives.
A, B, Up, C, A, C, A	Grants you all weapons at the beginning of the game.
B, A, Down, C, Right, A, B	Lets Harry practice the lever game.