For a track about hypersonic speed, it feels really chill and actually more on the slower side. The repetition, however, adds a sense of "slow motion", like this is what "fast" would sound like if it were considerably going at a lower speed.

It seems like the track picks up more after the halfway point, but I do like how it kind of drives in those super laidback vibes in the first half. Those off-beat accents in the continuum keep me engaged, and I like how, at the very end, you have the more higher synths harmonizing with the accented notes in that motif.

Overall, I wasn't crazy about this track when I first heard it, but it grows on me with repeated listens. Like, this definitely goes for atmosphere, and I feel that without a doubt. There's a very dark, futuristic feel, and I love the extended repetition and minimal changes that really add to this idea of "slow motion". I don't think that's really what you were going for, but I think it makes sense for a track with a title like "Hypersonic Speed". :P

I do agree that the lower ends are a bit muddy, but aside from that...I ultimately quite like this for the vibes.

Right off the bad, it sounds like you've got way too much reverb on your mix. I can hear it in those muddy low mids. Make sure you cut the low end in your reverb.

Your writing, bassline, and melody are actually interesting, with good timbre. Transition at 0:40 is super abrupt though. I may have even cut your intro if I were writing this piece. It almost reads like two intros back to back.

That said, I do like your chord progression. So few people just go for the easiest, daintiest sounding progression that sounds decent and leave it at that.

Biggest problem with this piece is mixing. Lots of instruments jumping in all over the place, too loud, etc., others covered up. Becomes especially apparent after 2:06, 2:40, and 3:23. I can deal with a long prog piece taking a while to go somewhere. It's harder when that piece also has instruments jabbing me in the eardrum on occasion. Feel me?

It also sounds like the mix did not have enough headroom before compression was applied. Recommend 3 to 6 dB headroom before you apply anything to your master channel. Might spend some time looking at various mixing and mastering tutorials as well. You've got a relative balance in between your bass and pads, but somewhere, something is happening with those leads, and even your snare sounds a bit too loud at times. Johnfn had a tutorial buried somewhere in his newsposts on using hi-pass and low-pass to get your instruments out of each other's way in the mix, frequency wise; you may want to ask him about it.

3:56, I love the idea of your outro, but that underlying bassy synth is over-reverbed, and it abruptly cuts off.

Like Kwing, I'd recommend condensing the piece, if not by a quarter, a half.

I like the timbre and the main melody, but I don't feel like enough was done with it. Without any dynamics or even progression (aside from a couple other bits popping in for a few measures before leaving just as suddenly) there's really not much here. The clapping sample you used also felt rather out of place.

I don't know if this would really benefit from trying to introduce progression, so my suggestion would be to look at all of the modifications you make to the main loop, pick out your favorites, and then condense them into a 1 minute loop rather than try to stretch it out to four minutes.