Asteroids Hyper 64

Enable cheat mode:
Pause the gameplay - and press the following button combination:
Hold L and press C-Left(2 times), C-Right(2 times), B, A, C-Up(2 times),
C-Down(2 times), Start.

Unlock credits, original asteroids and relentless mode:
Go to the main menu and press the following button combination:
Hold L and press C-Left, C-Right, C-Up, C-Down, A, C-Up, C-Down,
C-Left, C-Right, Start.

Classic Asteroids mini-game
Complete Zone 1, Level 15, after locate and shoot the green vector
asteroid that appears.