VomitHatSteve
Hat STYLE. Not contents.
But you don't have to mix in mono. Do you only have one monitor?
His left earbud stopped working and he can't get another set?
These days, mono is fine for demo recordings. If you just need to set down "this is what the band sounds like" for a press kit or something, you can do that in mono. But if you want something that people will be willing to buy, you should really use the full array of tools available, and that includes stereo mixes.
As to what's specifically wrong with this mix:
The band keeps losing the beat. If they can't play the song, there's no point to recording it.
The guitar is out of tune. If your instruments aren't in tune, it's always going to sound bad.
The guitar tone is bad. You somehow got it so sound simultaneously thin and weenie AND muddy. That's kind of impressive, but not a good thing.
The bass tone is worse. It's pretty much imperceptible the whole time. It just makes things muddier.
The vocals are buried.