The characters other than Hiroyuki and God are honestly pretty underdeveloped. But I think with this sort of comedy-type manga, it's not really too important since it's not the focus. But all of them are funny in their own right, especially the side characters like the old dude who helps make beer with them and that demon boar guy.
The art style is nothing to write home about, Hiroyuki purposely stands out in contrast to the others, and the way they draw reaction shots is pretty funny.
Overall, I think if you're looking for something to just read on your off time not expecting anything amazing, this manga is great for that. If you're expecting some gut-busting comedy or interesting story, then I think there are better places to find that.
