Welcome to modifications!

You've improved a lot, especially with scenery and just the general design of the maps. A bunch of areas are quite nice to look at!

Some critique: again, with the previous maps you've made, most all of the turns are sharp 90 degree turns. Not that 90-degree turns are bad by themselves, but some smooth, rounded, and sweeping turns in the pathways would make things feel more natural (especially in Green Hill, a natural place), and less "hallway"-like. Basically, less straight lines. Consider using slopes as well.

I feel like there's some textures that are a little out of place, such as the floors that hurt you in the first Green Hill act and the Jungle level having just regular grassy textures. There's also just a couple of meh textures, such as the Arid Canyon ones in Green Hill just overwhelming you with...orange colors everywhere.

The Chemical Lab feels pretty cramped, might wanna redesign that to be just a little more spacious. Snow Mountain looks quite nice in some areas, but then seems incomplete in some areas with lacking scenery and design.

Nice job!