Clever & Smart is an action game with puzzle elements, based on the Spanish comic book series Mortadelo y Filemón. The two protagonists are special agents and in this game they need to find Dr. Bakterius who was kidnapped by the competing agency OMA.
The main part of the game takes place on the city map which is shown from a top-down perspective (except persons, cars and trees). Here the protagonists need to explore the city and its sewers to find hints on Bakterius' location. However, there are many locations where Clever & Smart need to have certain items in their possession to proceed. For example to enter some houses Clever needs to use one of his trademark disguises or in the sewer they can tap telephone phone line with the right tools.
Another important resource is money which is used to buy items, disguises and food. The latter is essential for survival because a hunger value constantly rises when the heroes don't eat. Money is either earned by illegal activities like burglary or forging checks or by playing mini games like flipping coins or a snail race (Clever participating himself in disguise).