オルタナヴェルト -青の祓魔師 外伝- is an engaging 3D action RPG set in the popular dark fantasy universe of 青の祓魔師. Players take on the role of an exorcist, exploring the vibrant town of 正十字学園町 and engaging in various missions that blend action and storytelling. The game features an original storyline with full voice acting, allowing players to immerse themselves in the narrative while completing tasks that range from battling demons to assisting local residents.

With new characters designed by the original creator, the game presents an opportunity to experience the world of 青の祓魔師 from a fresh perspective. Players can utilize unique skills and elemental attributes in dynamic combat scenarios, and also engage in multiplayer challenges with friends. The game includes a customizable space for character interaction, enhancing the social aspect of the gameplay, while a talented voice cast brings the characters to life, making for a rich and entertaining gaming experience.