The player controls Inspector Gadget. When hit by an enemy, Gadget's clothing falls off, leaving him wearing only boxer shorts. The next hit causes Gadget to lose a life. Gadget's niece, Penny, and her dog, Brain, will assist Gadget during the game. Various gadgets than can be used included a helicopter rotor, a grabbing hand, some arrows, and an extending boxing glove. The upper case font used in this game is the same one used for Pac-Man, Space Invaders, and other video games of the 1980s. However, the lower case font used is original and was not used in any previous video games.
Something to note in this game is that Brain helps Gadget with only very minor tasks. Gadget is actually self-aware and fights the Mad Agents using a slapstick level of violence found in most children's video games during that era. At the end of every level except the sixth one, Dr. Claw would send a robotic claw arm attached to a chair (similar to the one Gadget "arrests" in the cartoon's opening) with some type of device aiding it. The levels are based on actual places from the television series. They are: Dracula's Castle, Clock Maker's clock tower in Switzerland, a South American jungle, King Tutonpoot's tomb in Egypt and Dr. Claw's Winterland Castle. At the end of the last level, Dr. Claw escapes into an airship.
But before going inside, he turns toward the player and his face is partly invisible. The player must destroy the ship so that he can proceed to fight Dr. Claw in his robot mech. After the fight, Claw would retreat and Gadget would save Penny from falling out of the ship. Chief Quimby would send Gadget a note informing Gadget that Dr. Claw had captured him after Penny was rescued.