An interesting direction you took here. You don't typically hear metal this barren, although that might not be a great thing here. I feel like you need more kinetic parts added to this. It almost feels like a bit of a death march? That would be really cool in theory, but this particular instance just comes off as really needlessly halted and almost uneasy. I wish you had more solos! That shit was super baller and it only happens like, once! Makes me think that this was rushed/left unfinished for the contest, but oh well. If that is the case, then you'll have plenty of room to add shit like that. Your guitar work for that section is pretty clean so it shouldn't;t be a problem.
I think this song is in need of some proper bass, as well as more of a prominent melody? I know this genre might be different, but you want to still make it interesting at the end of the day. This almost feels like an instrumental backing to a more polished/interesting song.
I don't think this song had to be 6 minutes long? It almost feels as if you're playing with one riff or a few power chords over and over again and not really doing anything with it, especially when you don't really have a clear melody to grab onto. The parts don't really seem that discernable from each other, and the weird quieter parts with morse code(?) seem rather pointless, just to break the flow you might have tried to maintain.
I guess I can sonically and mixing wise, it sounds pretty solid? Although that might be a result of it just being so minimal in general. With a bit more time and intricacies, I think you could really kick this song into high gear.