Sonic the Fighters

Sonic the Fighters sees the fuzzy blue mascot taking on Virtua Fighter, with mixed results. Due to Sega of America's fear of the game being seen as violent (despite its violence being 100% slapstick), the game saw an extremely limited release outside Japan.

A Saturn port was planned but never materialized, and the game remained an obscurity until Sonic Gems Collection.

Track 25
Present in the test menu's sound test. This might have been used for Honey's stage, but the official soundtrack release attributes a completely different and also unused song (Sunset Town) instead.

Expressions
There are several emotions and speech bubbles that are not used in the final.

Confusion or anguish. It likely would have been animated.

A speech bubble with "Yes!" written on it.

Another speech bubble with "Yes!", but it is all blue text here.

This particular bubble with "No!" written on it is just never seen.

The last of the unused speech bubbles.

Pinball Stage Leftovers
Remnants of a planned pinball stage, which was replaced with Casino Night.

Golden Gloves
Might have been some sort of power-up. Interestingly, the left hand's peace sign is one of the first objects programmed in the game.

Coordinate Object
An X, Y, Z coordinate object. This was probably used heavily during development.

Balls
These three balls were likely test objects, since they lack any real detail and are in a primitive state. This is supported by the fact that these are the first three objects programmed into the game.

Rocket
A rocket is in the game for some reason.

Container
This might have held the Flickies and bunnies seen below.

Flicky
It must have had some correlation with the Chaos Emeralds, as there is one Flicky for each Emerald and they are colored the same.

Bunny
It likely would have the same purpose as the Flicky mentioned above.

Alternate Bunny
An alternate version of the bunny model, which only has a blue-colored version.

Heart Outline
An outline of a heart.

Bell
Might have been used for an ending cutscene.

Pengo
He was likely supposed to make a cameo in Aurora Field.

Unplayable Characters
There are some characters who are inaccessible without using MAME cheats. Some of these were finished up and made available in the HD rerelease.

Honey
A yellow cat with black hair, based on Candy from Fighting Vipers, upon which Sonic the Fighters is based code-wise. She's nearly complete, except for a bug in her eye system and no between-level artwork (she uses Eggman's). Oddly, she has an alternate costume instead of a greyscale version.

The PlayStation 3 and Xbox 360 rerelease finished Honey's data and allowed her to be accessed by pressing Start over Amy on the character select screen (Arcade and offline versus only). Her between-level artwork is now just her silhouette rather than using Eggman's, and rather than having her name at the bottom it only says "???".

Metal Sonic
He hasn't got a greyscale version for mirror matches, like the Final Boss version of Eggman. He was made playable in the HD rerelease by pressing Start over Sonic on the character select screen (offline versus only).

Eggman's Mech
Eggman's stupid robot thing from the intro cutscene. Hasn't got a greyscale version for mirror matches. Head keeps rotating around for some reason. No player name or between-level artwork (it uses Eggman's). He has Final Boss Eggman's move set, except the triple punch uses purple speed lines instead of white.

Rocket Metal
Mecha Sonic Model No.29, seen briefly in the intro. Strangely, he actually has his own name graphic instead of defaulting to Eggman's.

Eggman
Everyone's favorite fat doctor, but without his mech from his Final Boss form. He has the same title card and name as his Final Boss form. His move set is the same as his Final Boss form, but with Knuckles-style punches.

Big Eggman
A larger version of the above character, ala the Fighting Vipers end boss. His model is broken when standing idle, but looks fine when moving or performing a move.

UFO Eggman
The little UFO Eggman uses to create greyscale clones for Mirror Matches. Has the default character moveset, since it clearly wasn't supposed to be fought.

Unused Eggman Form
There is one last unused Eggman form, but there's no model data except for some tank treads.