Sundown

Sundown is a single player combat and exploration driven Minecraft map. If you enjoy exploring unique and diverse areas, as well as upgrading your weapons and armor to take on enemies and bosses, then you may enjoy this map.

After rising from the grave, you set off on a quest in search of your brother to save the kingdom from certain ruin. Sundown will take you on a thrilling journey to distant lands on a grand scale. Battle your way through hand crafted dungeons, castles, and kingdoms to find answers about what happened to your brother, as well as discovering the truth about the world.

Sundown is meant to be played solo but there is a chance it may work in co-op. I never tested it.