Daikoukai Jidai (Japan), likely meaning "Great Ocean Age," is probably a strategy or role-playing game set during a period of exploration. The game may involve naval combat, exploration of new territories, and perhaps trade and resource management. Without additional research into Japanese game releases from the NES era, specifics on the developer and precise gameplay mechanics cannot be provided.

Daikoukai Jidai (Japan)

Dai Meiro - Meikyuu no Tatsujin (Japan) [En by Filler+KingMike v1.0] (~Great Maze - Master of the Maze)