At the start screen choose the following icons and enter the corresponding codes:
Big Red Icon:
Enter "JC" for 2-player boss games.
Daffy Duck Icon:
Enter "?BN" for all minigames.
Marvin Martian Icon:
Enter "#OP" for level select.
Taz Icon:
Enter "!WB" for no whack in boxes.
Tweety Icon:
Enter ".RT" for all gallery images.