The Game Boy Advance version of Finding Nemo adapts the Pixar film as a side-scrolling action game with light puzzle and exploration elements.
The game's 12 levels follow the plot of the film. Depending on the level, the player either controls clownfish Marlin or his son Nemo. Goals in the levels might include simply finding the exit, finding certain characters or items, reaching a certain point within a time limit, or simple survival, like when Marlin and his friend Dory are chased by Bruce the shark.
The levels are full of unfriendly sea creatures that shouldn't be touched and environmental hazards like strong currents. Simple puzzle solutions are used to get around some obstacles, like dropping a pearl into on oyster for it to close, pushing a piece of rock on a hole to block a current or flipping switches to open barriers.
Two levels deviate from the norm and are not side-scrollers. The camera is placed behind Marlin instead, who has to chase the character before him, taking care not to deviate from the path laid out by bubble rings.
Between levels, players can play a simple game of Concentration/Memory to unlock pictures in the game's gallery. Swimming through bubble rings during the levels gives additional chances in the mini-game.