It's quite a textural track, for sure, and it relies heavily on sound design, something that has been rarely explored in this contest yet. I don't think it necessarily needs a melody here because the track does have a solid structure and it does set a visual that is quite vivid and intense.
Without going again through what has already been said, I think the mastering is pretty spot-on, with the sudden bitcrush bursts probably being a bit too loud and disorienting -- In fact, I would have used them twice or three times at best and then switched to some other kind of noise/effect in order to keep things more interesting and fresh. We don't want our listeners to be deaf, and this track does have a great flow throughout the sections, so I'd suggest you to lower the mix just a tad bit in order to keep things listenable and at an acceptable level. The length of the piece itself doesn't lead me to any particular complaint, although you had a great base to build something even darker and mysterious, in my opinion.
Props for mastering Sytrus which is pretty resource-free and for ultimately experimenting with something that manages to be somewhat varied and interesting to listen to.
//FD