Original asteroids game:
Shoot the new, strange green object in Zone 1, Level 15 to unlock the original game.

Black hole warning
When small, white objects begin swirling around the eye of the black hole and become larger and in greater numbers, leave.

Solar flare attack
In Zone 3, Sun, stay away from the top left corner of the screen as much as possible. That is where the deadly solar flares always attack from.

Queen Worm
The Queen comes out of the purple crater and cannot be destroyed.

Cheat mode
During the game press start, then hold L and press C-Left, C-Left, C-Right, C-Right, B, A, C-Up, C-Up, C-Down, C-Down, Start.

Original Asteroids, credits, and relentless mode
When you are at the main menu, hold L and press C-Left, C-Right, C-Up, C-Down, A, C-Up, C-Down, C-Left, C-Right, Start.