Tomba! is a side-scrolling platformer in which players control Tomba, a wild boy on the search for his grandfather's bangle that was stolen by some evil pigs. Although Tomba is normally restricted to a two-dimensional plane, there are certain points where he can jump or climb onto a new plane. Tomba's main method of attack is to jump on top of enemies to grab them, allowing him to hop around on them before throwing them away. This can also be used to open other objects such as eggs or treasure chests. Tomba is also able to use various projectile weapons such as maces and boomerangs and can swing on branches and poles.

The game is based around a mission system, where the main character's (Tomba's) skills are employed to complete various tasks. Completion of a mission gives a certain amount of adventure points (AP) which are required for AP boxes which contain food (which gives you AP and restores 1 space of vitality) or items, and you may for example need 50,000 AP to open one. AP is also used to gain access to special places or information later in the game. Not all missions are necessary to progress in the game, however, they are required to achieve full completion. There are 130 events (missions) in the game, many of them rely on other events to be completed.