Not bad...
But you can't have such a scooped tone when you're doing a Mastodon cover. You have too much treble on your guitar and not enough on the bass. Also, I can hear when you pick, really loudly. Also, work on the volume differences in riffs. Drums aren't bad, almost nobody does their own drums on NG. I like this dude, maybe have somebody do vocals for it... (please note that I am always open to do vocal work by request lol). Good job man!