Rotate vehicle faster:
Press L1 or R1 at the gang selection screen to rotate your vehicle faster.

Soundtrack
Place the game disc in an audio CD player and play tracks two and above to hear music from the game.

Refill weapons, armor, and health:
Find a floating machine that is spinning slowly. When you go underneath it, yellow rings will heal you.

Defeating the last Boss:
First, go around the island and get one of the immortality shields. Then, go down the green tunnel and wait behind the wall. Shoot the small ships that beams the Boss from behind the wall. They will be destroyed after two or three hits from missiles. After killing all of them, use the shield and choose the strongest weapon you have (missiles or any sort of beam). Just stand still and you will kill it in about twenty seconds, if done correctly.