In 1893, an English archaeologist called Sir Evangel finds a strange stone in a London antiquary. The galopetra ("milk stone") has a hieroglyphic and a maze carved on one side, and a Minotaur on the reverse. Intrigued, he travels to Crete and starts to explore the newly discovered Knossos ruins. Searching the labyrinth, he stumbles upon a time machine, dubbing it the "Loony Machine". He leaves instructions at the site on how the device works, for future explorers willing to travel to 2000 years in the past and assume the role of Theseus, the slayer of the Minotaur.

Loony Labyrinth is the 4th pinball simulator created by LittleWing. It has one table with classic proto-Greek mythological themes. As an explorer and later as the legendary hero Theseus, the objective is to first find and activate the time machine, and then go back to ancient times and defeat the Minotaur.

In the first part, the goal is to collect all the five galopetra stones and install them to activate the machine. The ball has to hit drop targets near the stone ramp to make one of the STONE light letters start flashing. One stone is collected by sending the ball up the ramp while the light is blinking. Getting all the stones awards five million points. To install them, the ball has to hit several times the energy charger bumper, raising the energy level to 100% and turning on the install hole.

After traveling to 2000 B.C., the music changes and a multiball starts to indicate the switch. The goal is to rescue nine human sacrifices and kill the Minotaur. The LOONY LABYRINTH lights at the center of the table turn on to show the number of hostages, turning off with every saved victim. Shooting the labyrinth ramp rescues them one at time. After everyone is safe, a multiball starts where the player must sink three balls in the Minotaur chamber before the moon phase indicators near the flippers turn off, to defeat the creature and win the game.