The Battle of Olympus is an action-adventure game likely set in the world of Greek mythology. The US release suggests a focus on combat and adventure, probably featuring iconic characters and creatures from Greek mythology. While the specific gameplay mechanics would need further investigation, it likely followed the action-adventure formula common for NES titles of its era. The developer and publisher would require further research to ascertain. 

Battle of Olympus, The (USA)

Battle Fleet (Japan)