On the title screen, press 'F1' for player 1, 'F2' for player 2, or 'F3' for both players. Now type in the code word for which ever level you want and press 'RETURN'.
The game needs a joystick in port 2. Press 'FIRE' to be shown the player and level number, and press it again to begin play.
When playing: not all bad guys can be killed; the time bar near the bottom of the screen decays slowly, but decays faster if your craft is touching an Anti-Time block; the craft begins with a supply of 20 shots; up to 3 shots can be active at once; you begin with 3 lives; keep going until the craft can go no more, then the level will end; a bonus is awarded according to time taken; you can skip the bonus countdown by pressing 'FIRE'.
There is a high score table which you can get your name on if you are good enough. The properties of the magic yellow stars vary.
01-"START" | 08-"FLOOR" | 15-"CHESS"
02-"TRUTH" | 09-"PAPER" | 16-"WORLD"
03-"JELLY" | 10-"EARTH" | 17-"AUDIO"
04-"STORY" | 11-"SPACE" | 18-"LOGIC"
05-"CLOUD" | 12-"GENAM" | 19-"TITLE"
06-"MOUSE" | 13-"APPLE" | 20-"VENUS"
07-"HUMAN" | 14-"JUICE"
Also try the code "CHEAT".
On the title screen, type "HELO TO GORDON AND DAVEE". Start the game and you will be invincible.