Untold Story is a turn-based RPG taking inspiration from older traditional-styled JRPGs. The player will follow a main character, form a party with an assortment of other characters, and ultimately save the world. Each of the main characters will have their own unique role in battle, so mastering their skills is the key to success.

There is a large emphasis on story, world building, and character development. The world of Atomous is a huge place, with over 130 unique NPCs to meet and learn about. Untold Story focuses on themes of camaraderie, discovery, and adventure. But the world isn't a fully joyous place, and darker themes of death, depression and discrimination will be prevalent as well.

Untold Story follows Rover Wilson, an 18 year old learning how to use the Elements at Chilriva School. One day, he and his friends encounter a strange group meddling with that they called a "Monument", causing it to light up. After the confrontation, Rover and his friends are teleported away for an unknown reason, leaving Rover stranded alone in the middle of sea, far away from his home.

He is rescued by a band of pirates and, with their help, sets out on a quest to find the rest of his friends who teleported away with him. What begins as a simple quest to locate his friends becomes a quest to save the world by threatening its destruction. Along the way, Rover befriends several others who join him on his quest, and ends up learning more about the world, and himself, than he ever wished to know.