Those Sonic games have been great to have their maps seen, but playing through them is more enjoyable!
I've seen Sonic Advance's maps' sizes, and I was rather a bit disappointed to see them not larger/longer than Sonic 3 & Knuckles' maps, for any skilled player could, and many have, easily conquer them in less than minutes. Sure, they're all neat, but not truly long.
Then came Sonic Advance 2, and corrected the maps' length complaints people sent by having them six times larger, and I've seen how larger and longer they all have gotten! I was completely unsure how longer or shorter they could be, because their sizes weren't documented yet, but the former turned out true, and I loved the greater, longer length!
Even Egg Utopia Zone's Maps stand at their horizontal length range in the 30,000s, which not many games did... yet.
Sonic Rush went in, later on, and gave us the more longer Dead Line Zone, beating Egg Utopia's sizes by a more couple thousand pixels longer, nearing the 40,000 range, horizontally, that is.
Ok, Night Carnival, Act 2's length reached its greater length at about 41,948 pixels wide, but Dead Line Act 2 came close as the second longest level in the game.
Later again, Sonic Colors' DS version seemed to reach its longest level status yet. That would be Asteroid Coaster Act 2, reaching it at a whopping 44,256 pixels wide, and I see how its been a long ride, so to speak. Even speedrunners tried to conquer it as fast as they could, even going under 2 minutes & 30 seconds. Very impressive.
I previously thought any 2D game(not counting Metroidvanias in the mix) could try to top what size I hadn't seen yet, because they weren't documented yet, even Freedom Planet could've been that, but given the game was run on Clickteam's MMF2 engine, I strongly doubt their maps are close to that long size, cause that engine's size limit was at about 32,767, both horizontal and vertical(which didn't seem possible for lesser computers at that time, I can understand that).
So, I ask you this, even though some aren't fond of long levels, what is it you liked best about conquering them with what strategies used to do it?