TL;DR - Don't drop this anime because of the poor artwork and apparent rip off of other Isekai. It actually gets really good. It's worth watching. I personally enjoyed it immensely.
Did you give up on this anime when you realised it was an amalgamation of just about every other Isekai out there? Or maybe you had enough of it when you saw how piss-poor the backgrounds were. Or maybe even the sound. Or the poor animation.
I almost did. I'm so glad I kept watching. Yeah, this anime does feel like it copied a lot of its content from other Isekai such as Overlord and Konosuba, and yes, it does almost feel like a poor parody of those. However... I'm still so glad I kept watching.
It's actually GOOD! It's good BECAUSE it reminds me of those series. Anyway, I'll get to the meat of the review.
Story: Very Good! - The story is surprisingly heavy. There are a lot of underlying plots waiting to surface, and while at first, it seemed like Demon Lord, Retry was a straight forward self-service anime meant to capitalise on the boom that is Isekai, it becomes fairly intricate later down the line! I haven't even finished the series yet, I'm 11 episodes in as I write the review, yet I can't wait to find out what happens next!!
Art: Decent. - The first few episodes or so do NOT have decent art at all. I'd say the art was downright dreadful. The backgrounds looked lazy and poorly done. Like someone just smudged green around for forests, and brown for desert. However, at a certain point, the artwork improves significantly. Not only the character animation but the backgrounds as well. So, just get past the first three episodes or so and you might see what a delight this series actually is.
Sound: Good. - In the beginning, I had a poor opinion of the sound. The voice acting was fine but the background music seemed lazy and repetitive. Strangely, though, the more I listened to it, the more it grew on me. I started thinking 'Wow, this is actually pretty good. It makes the anime more fun, even if it sounds like a 12-year-old is playing their recorder to impress their parents. Haha, no, seriously, I think you'll enjoy the sound after a while.
Characters: Very Good! - The characters enhance the plot, and the plot enhances the characters. Demon Lord, Retry seems to be able to make all its characters interesting. Kunai's apparent harem has cute and funny characters, but they all actually have an interesting backstory. They're not just thrown into it. And even better is that the anime has a diverse cast and gives screentime to lots of characters, not just the main one.
Enjoyment: Great!! - Yep. Loved it. Kept me up nearly until daylight hours from the night because I just couldn't stop watching this one.
Overall: Very Good! - Okay, it has its flaws but I personally loved it. It could be seen as your temporary fix until Overlord Season 4 comes out or another Konosuba, or you can appreciate it for what it is and acknowledge it as its own show. That's what I'm doing. I think it's good enough. Really looking forward to more of this show! I sincerely hope it's a 24~ episode length series, and I hope even more that it has more than one season. It certainly seems to have enough groundwork for multiple seasons!