Select the 'Password' option at the 'Main' menu and type in the following codes to unlock the corresponding level in the game.

Unlock Level 2:
Enter the code JC! 511 111

Unlock Level 3:
Enter the code K6B M19 151

Unlock Level 4:
Enter the code 4WB M3! 1C1

Unlock Level 5:
Enter the code 5LS 15! 1M1

Unlock Level 6:
Enter the code N7T 56! 1M1

Unlock Level 7:
Enter the code *R4 F8Q 1W1

Unlock Level 8 Final Level:
Enter the code P85 29Q 132

Unlock Last Cutscene / Ending Credits:
Enter the code 975 V9Q 132

Enter the following codes to unlock the corresponding level.

Unlock Ship Level: ZGWYCR

Unlock Beach Level: PGCMMD

Unlock Forest Level: CNCGKG

Unlock Jungle Level: RGCKYD