What is the name of the cancelled Sonic game for the Sega Saturn?

The cancelled Sega Saturn Sonic game was Sonic X-treme. Developed primarily by Sega Technical Institute, it was planned as the Saturn's first fully 3D Sonic platformer and was intended for release during the 1996 holiday season.

The project had a troubled history. It began as a proposed side-scrolling Genesis game, moved toward the 32X, and was eventually redesigned for the Saturn and Windows as a third-person 3D platformer. One distinctive idea was its “Reflex Lens” camera, which created a fisheye perspective and allowed levels to rotate around a fixed center of gravity.

Development suffered from changing hardware plans, internal Sega disagreements, engine problems, and an extremely demanding schedule. Key developers Chris Senn and Chris Coffin became seriously ill, while the team struggled to meet its deadline. Sega cancelled the project in 1996 and formally announced the decision in early 1997.

Instead, Sega released a Saturn port of Sonic 3D Blast and the compilation Sonic Jam. The Saturn did not receive an original Sonic platform game. Sonic Adventure eventually filled that role on the Dreamcast, while some X-treme ideas and characters, including Chaos, influenced later Sonic projects.