Zoom! is a port of the Amiga game, without the smiley, but with a weird little alien thing instead. "C'mawn, boy."
Debug Memory Editor#
Press Start at the title screen to display the player selection screen. Press Up, Up, Down, Down, A, B. You seem to only have one chance to enter the code correctly; otherwise you'll need to either reset or wait for the demo to start. You may need to enter the code slowly to get it to register.
Several additional options will appear, including a sound test. Select the "DEBUG" option, begin game play, and press A. The screen will split and reveal the game's memory editor.
(Source: GManiac (Code correction))