Game manual description
"Who Turned Out The Lights?" appears to be the very poorly-lit basement of the Professor's laboratory. The secret level contains a number of pitch-black corridors, stairs to climb, drops, ledges for Jim to pull himself up on, high and low walkways, and doors. There are five multi-layered sections in total, which are entered through doorways.
Certain parts of the level are illuminated under dusty spotlights, but all else is inky blackness. For the most part, only Jim's eyes can be seen. There are a large number of power-ups, which may be easily noticeable, but still very difficult to reach due to having to perform maneuvers in the dark.
All the while, Jim will be hunted by the Professor's failed experiments, who like Jim are only visible as a pair of eyes. Although they are easily dispatched with the Plasma Blaster, they can inflict a lot of damage on Jim, and are very fast. However, it seems impossible for them to step into the light.
At the end of the level, in the fifth section, the spotlights run out, and a giant pair of the orange-red eyes will pursue Jim relentlessly. These giant belong to some unknown creature that is several times bigger than him. It will kill Jim upon contact, rapidly devouring him, Super Suit and all. This giant enemy cannot be defeated, and all you can do is flee from it. At the end, a triangle of spotlights acts as a teleporter back to Level 5.
- Unique, upbeat keyboard music plays during "Who Turned Out The Lights?". Game music composer Tommy Tallarico based this on "Maple Leaf Rag" by Scott Joplin. This music gets much faster, and much more frantic, as Jim runs from the giant unseen creature at the end of the level.
- "Who Turned Out The Lights?" was also featured with updated graphics and sound in the 1995 Special Edition of the game. However, the secret level was omitted from the 2010 HD remake.