The beast tribe of Gloo is causing trouble in town and it's up to Rubba to stop them. He isn't really trained in the art of direct magical combat, but he has of photographic counter-spells. His camera allows him to capture the magic missiles cast by his enemies and shoot them right back.
If you're feeling brave, you can use your camera's flash while standing directly in front of an enemy who is preparing to cast a magic. The sudden bright flash will startle the enemy into dropping its missile onto its head, inflicting major damage.