I believe this is what Spazzo is trying to say:
*) Let's add slopes! It's okay if we don't modify the physics.. just keep things perpendicular.
*) Why doesn't Sonic tilt with the slope? That is super lame. It also keeps me from making loops and he looks ridiculous on steep inclines! The real Sonic games don't do this!
*) Let's modify the physics (rewrite entire game logic to be based on a vector system). Let's create more sprites for every possible direction.
*) Owait, the PLR file is now about 10mb. Maybe we should move to models. Now we are abandoning software mode. Now we have to fix up OpenGL and make it work properly. Software mode runs like balls now anyway due to the slope calculations.
*) Editing tools need to be updated to work in a vector-based environment instead of an axis-aligned world. Maybe we should break Doom level format compatibility.
*) The official levels now look very flat and sucky. We should fix them up to take advantage of the new slopes. Some of this will involve revamping entire sections to take advantage of the features.
*) Modders get confused as hell trying to wrap their heads around a vector based game system. What's an UP vector? What's a cross product?
*) Congrats, you may as well write a new game from scratch.
If you don't believe it will follow this path, then you are a fool. Every feature we have added it has always left people wanting more, especially if it is to mimic what another Sonic game does. If you restrict gameplay to a certain set of rules, then the player adopts the
Suspension of Disbelief.
I should also add that making the game logic and physics work with a vector based system is no trivial task. It's seriously just like writing a whole new game.
It's one thing for a slow-moving marine to scoot around tight cooridors mowing down stupid demons to walk on a slope, it's another thing for a fast platforming character to do so.