after a quick listen if you want some feedback I think this needs more contrast in terms of instrumentation at least like what happens at around 1 minutes and 40 seconds.
Nuances in all aspects is good for the ear but if you stay to long for the same instrumentation, tonality, what ever it may become boring for the ear as is quickly get used to the sound.
Instead of the Guitar (i think) Having the main theme always try to give it to other instruments. Let them have sort of conversation so the speak where maybe the strings have the main theme then the Guitar becomes background element and then the Guitar takes over instead of mostly having the theme. I just think switching the main focus here and there could improve it overall. Maybe also some Rythmic variations as the Rythm or tempo seem to be constant through out. Maybe a few Nuances here could help as well.
I also think that the piece starts too sudden maybe spend a few minutes building up to it. It feels sort of like starting at a climax at the piece.
If you want some listening recommendation i would recommend
Mozart - Jupiter fourth movement (as it demonstrates what i am talking about regarding instruments having a conversation)
Maybe some music from Ramin Djawadi some of his horror music?
Like Slender Man, Game of thrones?
Maybe
Penderecki - Threnody
for inspiration.
Overall i think the concept is really promising. Good work.