Not much 'error' here, lad. That's excellent execution, tight enough arrangement for the genre, well sung (again, in keeping...) and well mixed. I've heard many studio sessions much, much worse that that. How to improve it..? Maybe a spot of post-prod Fx for the vocals, doubling the voice would be good (can be done 'live', now, with 'trickster' voice pedals. BV's would add, if there are others willing to step up to the hot plate. No need to be Caruso, just reasonably in tune. BV's add a lot to this sort of rock.
Excellent drum sound, so kudos for whoever tuned the kit. I can't hear much in the way of cymbals, but that's probably my advancing age and retreating hearing, so no worries. Best check with others to be sure, though.
All together a very efficient 'visiting card, so well done all involved.