It is a matter of coding the engine, if the game comes to a screeching halt if you let go off the D-Pad, and refuses to accept gravity and friction i.e. laws of physics, we have a problem. A problem that can be fixed by making changes in the engine. If the engine is modified the changes will affect episode I and any other successive episode.
You cannot though, how the levels have been designed is to go hand in hand with the very physics you want to change. SEGA stated this and people who've been trying to play Sonic the Hedgehog 4 as they would the original Sonic games are having trouble playing it as so and raging, they then go onto the internet to rant about why the physics are not the same, despite the fact they've been changed to accompany the current level design.
If they change the physics, the levels would have to then be redesigned themselves, you cannot just expect everything to full into piece. If you've ever tried designing a game, you'd understand even increasing a characters jumping height by a few pixels can have a great effect on what he can reach, let alone physics that could hurt certain levels, such as Casion Street Zone.
First of all, please stop using the word dead, classic Sonic has evolved into current Sonic, it is the same character just because he's taller and has visible Iris is not an indication of "DEATH". It is such a harsh word.
This thread encompasses the #1 problem with STH4, the physics not the character design and as far as I remember gravity and friction bearings were intact till Sonic Adventure 2.
I (And I assume MadeManG) were not talking about black eyed and pot belly Sonic, we were rather talking about the gameplay principles.
As I said, classic Sonic gameplay is dead, deal with it.
