Are you really amateur and doing it on your own?

Because it's awesome.

And in your case, that is a very good rhytm guitar sound: large and precise like about the riff at 0:30.

Good continuation, potential inside
I think it is awesome, vocals remind me of Deicide. The guitars are really dark sounding, like the presence control on the amp was turned low. But this may be the way you intended it to sound.

Nice work man, keep it up!
@BrunoChab and chris.morris.56

Thanks guys! (Having listened to your stuff,) I appreciate it very much.

Yep, only me I am afraid. Sometimes I wish I had some good fellow musicians; a bass player, a drummer, a vocalist, a guitarist… But then I realize I would probably fire myself and loose out on all the fun! :-)

I am fairly new to recording on my own and find mixing and mastering really difficult, especially with this type of music with an extremely crowded area of low-mid/ low-end. To achieve separation between the instruments is a challenge to say the least… In this respect, I don't think I cut it here - anyone with any tips and pointers?

Get (& stay) metal!