You know, I had a song called Claustrophobia back in the day. I think yours is better, haha.
I like that opening chord. It almost sounds like a ringtone.
Ah, now that everything's come in, I understand what you're doing with that.
I have to say, the mix is super mid heavy here. Does Amplitube come with a cab? If not there are cabs like NadIR or Kefir for free. Tames that fizzy noise on top.
Writing wise, this piece is great, if a little shaky in structure. I would not have repeated your breakdown at 2:40 twice -- I would have gotten back as quickly as possible to a final chorus. It sounds like you actually have two breakdowns one after the other, and the section you end with, right before the outro, I would have put where your distorted synths at 2:20-ish are.
Those synths by the way, I can't tell if that's a ring mod or something like Saturn distortion/saturation thrown on, but it's pretty sibilant and could probably use compression to tame it and take it down a bit.
Your modulation of effects throughout was very nice and adds touches that a lot of producers would have let go to waste. Some nice spicy moments.
The main issue to fix would be the mix. So I'll just try to parse out commentary by instrument
Drums, are not standing out in the mix when all instruments come in. This tells me either the drums are not very compressed, or the track is too compressed. I can't see the waveform since it doesn't like to display in my browser, but it sounds like there are actually just guitars covering them up, tbh.
Guitars, I would recommend something other than FL Slayer, or at least modulate velocity more. For guitars, you'll want something you can actually doubletrack without phasing, and that isn't going to sound so boxy in an amp. There's a lot of 250 hz range noise it sounds like, trying to mix in that aggressive tone. I recommend for mixing guitars a quick search on Chernobyl Studios on YT. He uses reaEQ to cut out everything on that guitar send to up to 250 hz. It helps.
This said there are good uses of Slayer, and it does not ALWAYS sound bad, but those are when the instrument is played to its strengths, which is obvious synth keytar solos, not rhythm guitar. There are lots of free guitars on the net. I would at this point even recommend something like Ample Sound's free Taylor, if you can find a way to cut off the reverb. Then I think there's a junk guitar for Kontakt, among others. Look around, I'm sure you'll find something. I think there's a Kontakt factory that offers freebies, and you can work up enough kredits doing reviews or product demos with that to afford instruments, if that's your thing.
Mix wise I think the drums and bass need to stand out more. That mostly just means turning everything else down until you can clearly hear everything. Some people recommend mixing in mono to achieve a cleaner sound profile and cutting down on reverb as much as possible.
When I was working at this stage I would then render the file at -6 dB and see if I could find a free mastering service. Helps if you want the raw product out without spending a day on the master channel.
Thanks for coming out to NGUAC!