Get Unlimited Lives:
Pause the game and hold CTRL then put in the code Down, Down, Up, Down, Right, Down, Up, Up

Get All Levels:
Pause the game and hold CTRL then put in the code Up, Down, Left, Right, Right, Right, Down, Left

Get All Characters:
Pause the game and hold CTRL then put in the code Left, Right, Left, Left, Left, Up, Left, Left

Get All Extras:
This code allows you to open mini frogs, feeding frenzy, and frogger artwork. Pause the game then hold down 'CTRL' and then press: Right, Up, Up, Down, Right, Right, Down, Right