In terms of Sonic 3 & Knuckles, you have to remember that even though Sonic may have not had access to certain paths that Tails and Knuckles had, his paths still had alternate routes. This is probably why the game is so huge (and why debug mode is so much fun when it comes to exploring different paths with different characters, I.e. Knuckles' routes with Sonic)
In terms of Super Mario World, that game (and 2D Mario games in general, if I'm not mistaken) did exploration a little differently. At first glance, it's always "go from the left to the right" in terms of level completion; there are few, if any, branching paths. However, Super Mario World is filled with tons of little secrets... a pipe that you need a little skill to reach, a secret block that's kinda sorta hinted at that will reveal a vine to climb up and get some goodies, flight that could lead to another area, etc. And that's what made Super Mario World so great, trying to find all the little secrets and one up tricks and everything else that makes Mario Mario.
As far as Chemical Plant goes, you can definitely avoid the water completely if 1) you take this pretty badass shortcut (I know its TAS, but you don't need tools to make it)or 2) you take this alternate path that no one seems to know about.
In terms of Super Mario World, that game (and 2D Mario games in general, if I'm not mistaken) did exploration a little differently. At first glance, it's always "go from the left to the right" in terms of level completion; there are few, if any, branching paths. However, Super Mario World is filled with tons of little secrets... a pipe that you need a little skill to reach, a secret block that's kinda sorta hinted at that will reveal a vine to climb up and get some goodies, flight that could lead to another area, etc. And that's what made Super Mario World so great, trying to find all the little secrets and one up tricks and everything else that makes Mario Mario.
As far as Chemical Plant goes, you can definitely avoid the water completely if 1) you take this pretty badass shortcut (I know its TAS, but you don't need tools to make it)or 2) you take this alternate path that no one seems to know about.


