Odama blends tactical wargaming with pinball gameplay. The game takes place in a feudal Japan setting. The main character is a young general named Yamanouchi Kagetora, who is intent on avenging his father's death by reviving the most ingenious weapon ever to hit the medieval battlefield: the Odama.

The Odama is a gigantic ball powerful enough to destroy whatever it strikes, friend or foe. Using giant flippers, players aim the Odama to bowl over enemies, shatter their defenses and wreak havoc on the battlefield. With the Nintendo GameCube Microphone, players direct their soldiers out of the Odama's way and into the fray by charging the enemy, defending positions and seizing the enemy gates.