Sonic the Hedgehog (Xbox 360)

Widely regarded as the nadir of the series by most, Sonic the Hedgehog (often referred to as "Sonic '06" to distinguish it from the 16-bit original) was heavily, extensively rushed and as a result contains lots of bugs, unfinished content, and leftovers of things intended to be finished.

Also, loading. SO MUCH LOADING.

Unused Character Intro Animations
By swapping character files of some Amigo mode characters with those of regular characters they will be shown to have a character select screen animation.

Unused Icons/Rainbow Gem
Some of these HUD icons are not used in the game. The first 7 gems are normally obtainable, however the rainbow colored gem is not. The demo version has text that says "Allows you to perform 'super'", which is replaced with "???: You'll need to buy it to see what it does!" in the final.

Originally, there was going to be a gem that could be purchased at the store which would allow you to play as Super Sonic in more than just the final stage (similar to how it was in Sonic 2, Sonic 3, and Sonic & Knuckles whenever all seven Chaos Emeralds were collected), but that feature was removed from the final most likely because of its rushed development.

This said, the item can still be accessed through hacking, but isn't fully functional. What it does is make Sonic float in place like Super Sonic for a few seconds. It appears to be the transformation animation, which otherwise only happens in a certain cut-scene.

Unused Shield
In the "POWER-UP ITEMS" section of the game's manual, the "Shield" is listed as an available Power-Up that can be obtained from Item Boxes, yet no Shield Power-Up Item Boxes are ever seen anywhere in-game. It was probably scrapped due to time constraints.

A Shield can still be activated in the final game via modifications, though its programming is incomplete, and it doesn't actually protect you from damage. It is not clear if this is the same Shield as the one listed in the game's manual.

Unused Warp Gate Images
These images are displayed on the warp gates that appear on the Soleanna map, among which are levels that do not have warp gates, such as Crisis City.

Knuckles Has Cleared Act 1
Despite not being able to normally finish a level, Knuckles has a proper level-completion animation and a set of voiceovers for responding to his rank. Knuckles CAN finish one of the levels (Flame Core) with the use of a few glitches, allowing for these quotes to be heard.
 * S Rank - "All right!" [[File:KnucklesClearS.ogg]]
 * A Rank - "That felt good" [[File:KnucklesClearA.ogg]]
 * B Rank - "Well that wasn't TOO bad" [[File:KnucklesClearB.ogg]]
 * C Rank - "Hmph, that took longer than I thought." [[File:SonicTheHedgehog06_KnucklesClearC.ogg]]
 * D Rank - "Shoot! I've still got a ways to go..." [[File:SonicTheHedgehog06_KnucklesClearD.ogg]]

Unused Music
There are three unused audio tracks on the disc, silver_theme.xma, main_theme.xma and shadow_theme.xma. Silver's track seems to have MIDI backing put in place, Sonic's has no vocals, while Shadow's theme is an untouched version from Shadow the Hedgehog.

A demo version of His World, Sonic's theme for this game. It has a clap track, probably to guide Ali in singing it.

Unused Text
The following text can be found by examining the disc's contents. It is unused in the game.

Shop Text
This is text which was meant to be used in the shop. The ??? item may have been the unused Rainbow/Super Gem item. Silver was to have a Speed up item to increase his maximum speed. Music from previous games also looked like it was once purchasable. This concept was later seen in Sonic Generations.

Allows you to use the "Light Dash." By using the Light Dash, you can move quickly through a trail of Rings. Allows you to use "Sliding." By sliding, you can attack enemies while moving. Allows you to use the "Bound Jump." This lets you jump to higher places and attack below you. Allows you to use the "Tornado" custom action. Creates wind to attack surrounding enemies. Allows you to use the "Slow" custom action. Slows the flow of time in the immediate area. Allows you to use the "Mach Speed" custom action. Enables you to do a Supersonic Boost Dash. Allows you to use the "Homing Smash" custom action. Enables you to stop in midair, and do a Homing Smash Attack. Allows you to use the "Gun Drive" custom action. Enables you to throw an Gem and teleport to that location. Allows you to use the"Thunder Guard" custom action. Defends against attacks while attracting nearby Rings. Allows you to use the "Scale"custom action. Changes Sonic's size. ??? You'll need to buy it to see what it does! Allows you to use the "Light Dash." By using the Light Dash, you can move quickly through a trail of Rings. "Chaos Boost Level 1." During the boost you will be granted "Chaos Snap," an upgrade to Chaos Attack and Chaos Smash. "Chaos Boost Level 2." During the boost you will be granted "Chaos Lance," an upgrade to Chaos Spear. "Chaos Boost Level 3." During the boost you will be able to activate "Chaos Blast." Allows you to use "Hold Smash." This allows you to throw what you have grabbed in a single throw. Allows you to use "Grab-All." This allows you to grab things in a wider range. Press the $ button twice quickly to perform "Teleport Dash." This allows you to do instantaneous Teleport Dashes. Hold the $ button during jump to perform "Psychoshock." This allows you to stun nearby enemies and grab them. Allows you to "Speed Up." This increases your movement speed. A 1-up item. "Sonic Adventure" music "Sonic Adventure 2" music "Sonic Heroes" music "Shadow The Hedgehog" music "Sonic The Hedgehog" music "Sonic The Hedgehog 2" music "Sonic The Hedgehog 3" music "Sonic & Knuckles" music "Sonic 3D Blast" music "Sonic R" music "Sonic Riders" music "Sonic Adventure" music, part 2 "Sonic Adventure" music, part 3 "Sonic Adventure 2" music, part 2 "Sonic Adventure 2" music, part 3 "Sonic Heroes" music, part 2 "Sonic Heroes" music, part 3 "Shadow The Hedgehog" music, part 2 "Shadow The Hedgehog" music, part 3 "Sonic The Hedgehog" music, part 2 "Sonic The Hedgehog" music, part 3 "Sonic The Hedgehog 2" music, part 2 "Sonic The Hedgehog 2" music, part 3 "Sonic The Hedgehog 3" music, part 2 "Sonic The Hedgehog 3" music, part 3

Main Menu Text
Text which was meant to be used on the main menu but was scrapped. Notable text includes the mention of a "very hard" mode, additional episodes for Amigo characters, and additional missions for Metal Sonic (who isn't even in the game at ALL, let alone in a playable form).

You can play a new set of very hard missions for Sonic. You can play a new set of super hard missions for Sonic. You can play a new set of extra missions for Sonic. You can play a new set of very hard missions for Shadow. You can play a new set of super hard missions for Shadow. You can play a new set of extra missions for Shadow. You can play a new set of very hard missions for Silver. You can play a new set of super hard missions for Silver. You can play a new set of extra missions for Silver. You can play a new set of very hard missions for Sonic,Shadow, and Silver. You can play a new set of super hard missions for Sonic, Shadow, and Silver. You can play a new set of extra missions for Sonic, Shadow, and Silver. You can play an additional episode for Tails. You can play an additional episode for Knuckles. You can play an additional episode for Amy. You can play an additional episode for Blaze. You can play an additional episode for Rouge. You can play an additional episode for Omega. You can play an additional episode for Metal Sonic. You can play additional missions for Tails. You can play additional missions for Knuckles. You can play additional missions for Amy. You can play additional missions for Blaze. You can play additional missions for Rouge. You can play additional missions for Omega. You can play additional missions for Metal Sonic.

Other Unused Text
Some of these missions are seen in-game (the $ is a variable and can be made to mean anything), but others aren't. It seems that Sonic Adventure 2-style goals were once meant to be part of the game, as well as a mode where more than one Goal Ring was located in the level.

Get to the Goal Ring! Get to the goal within $ minutes! Collect $ rings! Defeat all enemies! Wipe out all enemies! Get to the goal within $ minutes! Collect $ rings! Get to the goal before your rival! Get to the goal before the ghost! Find $ Chao! Find the Goal Ring! Get to the new Goal Ring! Clear the minigame! Clear hard mode!