Galaga - Disarming Enemies
Just as in the arcade game, the Nintendo 64 version has the same cheat. In stage one, allow all enemies to get into formation, the bottom left-hand bee is the key to the cheat. Kill all of the other enemies except for him. After eliminating everyone except for him, place your ship in the bottom right hand corner. Allow him to fly around and attempt to bomb you. After one pass with him not firing, allow him to pass again and if he is still not firing shoot him during this second pass. This will take approximately 15 minutes. This will disarm enemies for the rest of the game.

Galaga - Double fighter
Shoot one of the green ships on the top row to turn it blue. When one of them dives alone, avoid its shots. Intentionally allow your fighter to be captured by its tractor beam. With your next ship, wait until the joined ships to dive. Shoot the alien while carefully avoiding your captured fighter. You will have a double fighter with twice the firepower.

Pole Position - Starting Tip
Here's a cool tip to start a race. When the race starts, start in low gear. Then wait a few seconds until you reach 160k/m or so, then press R to change to high gear. You will get a nice head start!