Pretty nice level, it's a little on the short side, but not bad.
small issues would be the tube being pretty slow, I tried to spin dash in it, or even use modern sonic to boost in it and it always being at that pace feels off, I do like the detail of the yellow boy passing by before you encounter him, when traveling in the tube.
I like the verity in the stage, a short 2D section that turns into a minecart section, I think it was nice change of pace to the earlier section being a more enclosed box, unless there is a secret act 2 I would be happy to see an act 2 of this as I think the ideas place in it are pretty cool, but after beating I was left wanting more, which is pretty good because I did enjoy it enough to want a little more, I feel a update or act 2 could really flesh it out more.
Overall it's a good level, and I can see myself replaying it to find out more hidden stuff in the map, I don't know what the game means by "I shouldn't have done that" when I dabbed on the grave as pointy sonic, very interesting and I'm hooked on finding out.
a pleasant level. sometimes the sense of direction is a bit confusing, but at least each room is distinct enough for the player to realize when they're going backwards. zoom tube section is also a bit slow, but it goes along with groovy music so i can't complain too much.
the 2d section was great, and you did a good job building around the atmosphere. even though the stage was meant for sonic, there was really only one instance where playing a nospin felt "out of place" for me.
custom things are done well too, silver rings are more fun to collect than normal rings and the boss was well introduced and actually fun to fight. the secret was 100% worth it to find and do, i recommend no-lifeing this level until you get it.
Honestly a really cool little zone with a lot of variety. Was genuinely surprised to see the DKC silhouette and minecart combo, but it was great nonetheless and gave the map a lot of spice. Hope to see more from you in the future