Most of this piece kind of feels to me like a cartoon-y top-down retro video game like, say, Pokemon, where there's a vague sense of danger or eerie feeling of "It's too quiet...". This lasts until about 2:24 in, near the end of the piece. At that point, the instrumentation starts to phase out and that feeling goes away.

If you intend on looping your piece, I suggest changing the end of the song so it loops more cleanly, rather than just phasing out the instrumentation like you did.

As far as darkness goes, I think you're getting there, like I said earlier. As far as "mystics" goes, I don't know what you mean. Could you elaborate on that? It would help me better understand what you are trying to do and, as a result, I may be more able to give helpful feedback.

I'm confused why you tagged this as Trance music. IMO Video Game would be a better genre name. When people expect trance but get a video game oriented song it's like drinking grape juice when you expect wine; not bad, but not what is expected. Speaking from my own experience, this change may seem small, but not making it could ultimately alter how people perceive your song in a way that is not helpful.

I hope you find this review useful. :)

More info about how I review music here: https://codefreq.newgrounds.com/news/post/1089806