Begin a two-player game, and press [Esc] + Fire on both joysticks at the same time.

Press [Esc] and then type "yep, i changed the cheat mode on this version", and press [Enter] at the title screen. Begin gameplay and the screen will be flipped upside down.

Load or reset the game, then execute the following BASIC command before running or restarting the program.

Choose the ''2 Player'' game where you are able to knock out the other player. Once the first screen of foes is defeated, knock out the other player. Each time you defeat the other player, you get a 1UP.

When playing the stage that you are inside the helicopter, there is a way to make the door close as soon as it opens. After it opens, just pause the game and leave it paused for about 10 or so seconds, and then unpause the game. After unpausing the game, the door should close, saving you the hassle of worrying about getting sucked out, and you can just concentrate on the enemies.

Take your character down to his last life. When you first encounter the train in Mission Five, you should have only three bars of health left. Now you want to lose two of those health bars. Then jump up and get hit by the upper steam pipe (losing your last bar of health) as the train is moving backwards. You should fall on the front conveyor and bounce around there for a little while. When you stand up again, if you did this right, you’ll have unlimited lives.

At the title screen, hold Button 1 + Button 2 + Select, wait until the screens starts fading into the intro and just before the screen goes totally black, hold the Start button. If done right, instead of going into the intro, it will go into the Visual Test Menu.

At the title screen, press II, I, II, I, Run. The Sprite Test should appear right away.