Looney Tunes: Duck Dodgers [N64]

Animal sounds:
Press B on Planet X, Transformation Zap to hear an animal sound. For example, when you are a chicken, press B to hear a crowing noise.

Easy lives:
Successfully complete the basketball mini-game, but do not return to the main game. Jump on the button to play the mini-game again. Only two balls will be there. After successfully completing the mini-game, an extra life will be awarded. Play the mini-game again and only one ball will be there. Successfully complete the mini-game to earn yet another extra life.

When you are on Planet P and in the Ancient Pyramid, go to where the man with the big button in front of him is located. Keep pushing it until it runs out, then exit the pyramid. Go back in and keep pushing the button. When you get 50 energy, you will earn an extra life.