On the high score table enter your name as "WIGAN NINJA", to recieve infinite lives. Also if you get a score of 50,000 or more die and type "SPECCY MODE" on the high score table. This will give you twice as many enemies. Press 'F8', 'F7', 'F6', 'F5', 'F4', 'F3', 'F8' and then 'F1' three times (oR 'F2' three times) ('F1' and 'F2' are for what player is to have the sight). This will give you the laser sight thoughout the game. Also, type "EDOM TAEHC" on the high score table for infinite lives.
Usually you have to shoot equipment boxes to get the laser sight, but press 'F8' and fire at the same time on the title screen and you will start a 1 player game with laser sight. For 2 players press 'F2' instead of 'F8' on the title screen.