I can't describe it, but this level is somehow unusual, and for some reason I feel like I'm playing Celeste rather than SRB2. I like that the level doesn't try to seem like a "level," but rather like literally mountains high up that you can explore, something very few levels manage to do (immerse in the atmosphere). I don't know, but for some reason I'd like to think this level was created in 2.1 because of the old-fashioned design. that's not a bad thing.
as I recall, this is one of my highly rated levels, and even now, having played it again, I still enjoy it, even though there are some questionable things like the boss at the end of the level, outdated decorations, questionable design decisions, and the fact that this level is really difficult for characters like Sonic or Amy.
