Proto:Sonic the Hedgehog (2006)

This page details one or more prototype versions of Sonic the Hedgehog (2006).

To do: Document the prototype DLC Known differences include potentially different Hard mode layouts used as placeholder, as well as an original mission for Shadow's White Acropolis Extra.

Xbox Live Arcade Demo

Xbox Live Arcade Demo Dated September 16, 2006. A shortened version of the TGS 2006 demo released on Xbox Live Arcade on September 27. Some of what's playable is a little more polished than the final, but under the hood the game's far more incomplete.

Review Version

A heavily corrupted review version of the game was found in 2019 and is currently being restored; all of the recovered data seem to be identical barring duplicate stage files and the executable.

(Source: Sonic Retro)

Prototype DLCs

In 2022, a large leak was released onto HiddenPalace by ObscureGamers, and in Feb 2025, eleven early DLCs for Sonic 06 were found and dumped on it, and include early versions of the released Very Hard DLC, as well as extremely early versions of the planned Super Hard, Extra, and Amigo character DLCs that were ultimately scrapped later in development. The two Boss Attack DLC that were found are seemingly the same as the final versions.

Very Hard Prototypes Date unknown, but before January 2007. Prototype versions of Sonic, Shadow, and Silver's Very Hard DLC that was eventually released. They are listed under DLC DOWNLOAD TEST0003 A, DLC DOWNLOAD TEST0003 B, and DLC DOWNLOAD TEST0003 C, respectively.

Download Test Prototype Date unknown, but before January 2007. A test/prototype for what was planned to be the amigo character DLC stories that was later seemingly refitted into Team Attack Amigo, as it uses the same folder. It is listed under DLC DOWNLOAD TEST0001.

Super Hard Prototypes Date unknown, but before January 2007. Prototype versions of Shadow and Silver's scrapped Super Hard DLC. They are listed under DLC DOWNLOAD TEST0003 D and DLC DOWNLOAD TEST0003 E respectively.

Extra Mission Prototypes Date unknown, but before January 2007. Prototype versions of Sonic, Shadow, and Silver's scrapped Extra missions DLC.

(Source: Hidden Palace)