KojiChao managed to rip open the PC version of the game and unveiled some weird stuff that just has to be posted here.

This is a background-less image of The Final Weapon's final form. My guess is that it was used for an ending screen of sorts for the "Bad Ending", or perhaps, with some explosions, a low-budget animation of the final boss blowing to smithereens (take some animated explosions and paste it there to see what I mean). It puzzles me to see that the background is entirely black without the Sonic Crackers-ish metalic stuff placed underneath the 3D arena. Maybe it's a direct port of the Saturn image (I've never seen the Saturn version of Sonic 3D, only the PC and Mega Drive ones, so you'll have to forgive me) or something.
Notice the pathway leaing up and right.
Just one more thing...the boss here is fully equipped; he has the fire breathing nose from his second phase, the rocket launcher from the fourth phase, and the gun from the fifth phase. Whatever happened to the parts from phase 1 and 3 is beyond me...perhaps it has something to do with the fact that the arms used there aren't directly attached to the prerendered model? Weird.

Well, this is the background for the options screen. Entirely innocent besides the small fact that there is no options screen in the game. Both the Saturn and MD versions have options screens with backgrounds similar to this pic, but the PC version itself is completly lacking. This somewhat cool feature has been replaced by a dull geeksih Windows menu. Which isn't even visible during the game and messes up my graphics card whenever I access it. Oh well.

Well. I know some people are going to think strange things after seeing these pics. Nonetheless, they were seemingly used as "loading" screens between the regular game and the Special Stages. Touch Tails and you get the first one. Touch Knuckles (...PERVERT.) and you get the second one.

Like I said before, thanks to KojiChao for these.