Sonic Mega Collection

Sonic Mega Collection wasn't the first compilation of Sonic games, but it sold well enough for Sega to produce oh-so-many-more ports of classic games.

Japan-Exclusive Games
Comix Zone and The Ooze are only available in the Japanese version, and even then can only be unlocked with button codes:
 * Comix Zone - Press Up, L, Down, R, Up, Z, Down, L, Up, R, Down, Z in the Options menu.
 * The Ooze - Press Z, Z, Z, Up, Up, Up, Down, Down, Down, L, R, Z in the Manual menu.

Both games were included in all releases of Sonic Mega Collection Plus.

Unused Music
A three-and-a-half minute track used for a video intended to demonstrate the capabilities of the Sofdec codec (see below).

A track from the Sonic Adventure 2 multiplayer menu, probably meant to test the ADX music format.

Old Menu
An early version of the Games menu is in the disc, albeit mostly in Japanese. It is clearly from an earlier stage than the leaked prototype, which uses the final menu style. This menu translates to:

"GAMES Sonic the Hedgehog Sonic the Hedgehog 2 Dr. Robotnik's Mean Bean Machine Ristar the Shooting Star Flicky Monster Lair Vectorman"

The other listings are a series of A's in hiragana. Vectorman was eventually included with Sonic Gems Collection, while Monster Lair (part of the Wonder Boy series) was not put in any collection. A 3DS Max model file of the menu is in the ISO, as well as a breakdown of all the menu's textures in PNG.

Sonic CD Remnants
Sonic CD was going to be in the collection, but was cut due to emulation issues and a supposed lack of space (but see below). A scan of the European manual is still in the collection's files, however, while gameselect.tpl contains an image with crude Japanese writing of " ソニック CD " ("Sonic CD").

Both the manual and image can be accessed normally in the prototype, as Sonic CD is in the Games menu.

Unused Movies
Three short movies were found inside the data. Sega is not credited on any of them, and none are even remotely related to Sonic.

sample.sfd
XKfHJrLYTe0 A test video for CRI's Sofdec video compression technique for developers. If opened by FFPlay or a similar player that can play Sofdec/ADX files, the unused song is played as well.

loopbgv.sfd
ziXdXn79zzo A 12-second soundless CG water rippling effect somewhat like the Sonic Team logo animation of Sonic Adventure. The purpose of this clip, aside from showing off Sofdec's capabilities, is currently unknown.

smpinter.sfd
fVWOR1w77WI A 30-second clip of San Francisco which might be from CRI, since they do have offices there. It is suspected to be a test clip from the Dreamcast development kit.

It is likely that Sega was testing the Sofdec player and simply didn't take these files out, but the movies and song take up roughly 20% of the data and even then there's empty space on the disc. This space (and the space taken by the other unused stuff) could have easily been used for more games...including Sonic CD, which allegedly couldn't be included partly because of "space limitations".

Demo Graphics
Present in the demo folder are .tpl files which have graphics for a demo, all in Japanese. Notably, the first picture uses the layout of the prototype title screen.



The title screens of the games, though some are blacked out:



And finally, there is screen for when the demo ends:

Thank you for playing. Hang on for the eminently playable Sonic Mega Collection, planned for release this winter!