Playing Build 808. "3D Bonus Stage" is accessible from the main menu. This was removed in the final, but a screenshot of the option exists in the american manual for the game. Was this in the Japanese build? Time Attack is accessible from the start without having to enter a cheat code. Sound Test is accessible from the start without having to enter a cheat code. Water in Great Turquoise Act 1 seems to be white instead of blue. I don't have the final ROM handy, but it seems there are some sprite changes. Sonic's walking animation has dithering around his face and Knuckles seems to have what can be best described as a milk mustache. Playing up to Meta Junglira Act 1, I notice nothing else immediately different about this.
<!--quoteo(post=180014:date=Feb 23 2008, 08:42 PM:name=BlazeHedgehog)--><div class='quotetop'>QUOTE (BlazeHedgehog @ Feb 23 2008, 08:42 PM) 0816: Final: "3D Bonus Stage" is missing from the menu in 0816. Also, Time Attack and Sound Test are unlocked by default in the final as well. Perhaps there's changes later in the game?
I played through all of 808 (excepting the 3rd-5th special stages) and didn't notice any differences from the final other than the 3D Stage option being present at the beginning.
Wait, are you sure? I checked on Gamefaqs and they implied they were only unlocked via cheat codes: And I know I never remember seeing any Time Attack option before.
It's no more a cheat than it is to enable only teleporter items in Sonic 2. They both definitely were available in the Sonic & Tails 2 (the JP version) main menu. It's hard to see since "press start" tends to flash over the options listed at the title screen.
For more shits and giggles, cheats! Always Have "2" Rings - 00D159:32 Always Have "32" Lives - 00D140:32
You also have to press UP or DOWN to access them in the 808 prototype. I suspect that "cheat" confused the SEGA logo with the title screen. :P