Never played Sonic CD, but I don't need to i n order to say that this level looks really nice. Love how you used all tiles that could've been for creating mechanical parts. The BG itself is breathtaking too.
I like the way this looks so far. The colours do remind me of Sonic CD (which is a good think, by the way). The strange metal structures in the desert makes me think of Area 51. I think the level would benefit from more variation in decoration, though. For example, fewer patches of grass and maybe more creative styles of cactus and other desert plants. Mirage Saloon in Sonic Mania will give you some inspiration.
I can't remember exactly, but do those timed lifts respawn? Right now, the aesthetics look amazing, the design is pretty simple. I would like to see the timed platforms used in creative ways in conjunction with saws, which would make for really interesting and fun design.
This is like a mix of the Painted Desert and a Mega Man level. I like some of the setups that you've made along with the palette of the level overall. And I'm a sucker for Rexes. It could use some more enemies, though, assuming the Pokey/cactus things don't hurt Mario.
I think the green looks perfect, it's a good contrast: the mechanical green industry with the desert-like environment. Aesthetics are basically perfect in this level, I can't find anything wrong with it.
It's nice to see you're using the timed lifts and saws, they have a lot of potential. The only thing I would say is, don't be afraid to expand on your ideas. Your vldc9 level was really good, but it's like a "tip of the iceberg" kind of level. It just brushes the surface of what you could have done with your ideas. It's possible to expand fully on your ideas without making the level become too difficult. I always use worldpeace as an example, but in this case he really is the best at doing this.