At the main menu, select "Load Game" to get to the password input screen. Note that all passwords read clockwise starting from the topmost letter on the screen. Hold A while entering to see what you're doing.
Password: Level 1PWK47: Break-in at the O'Connell Mansion K3J178: The Rescue XS0N0C: Bus Getaway N0N1F1: Canyon Chase B4S6L7: Arrival at the Oasis 144W88: Into the Pyramid RDV011: Final Escape 64P51T: Ending