At the title screen, hold I + II + Select and press Run.
At the title screen, press Run. While the screen is fading out, press and hold II. When the screen fully goes black, press Run the number of times listed in the table below for the desired level, then release II to start.
The object on the title screen reads "PARANOIA" in the Japanese version, and bears an image of a creature in the US version. The latter also adds "FROM NEC" underneath the title, stretches out the "PUSH RUN BUTTON" text, and moves the copyright to the lower right corner.
Round Clear Screen
In the Japanese version, the creature seen between stages laughs with its middle finger raised. In the US version, it simply waves its index finger while saying "Come On!"