In hindsight I probably should've expected this especially since it's a 5ep ONA with Netflix and J.C. Staff (both of which are mixed bags when it comes to anime), but I was blinded by excitement over the manga getting an adaptation of sorts. The whole thing is kind of a hot mess and I'm not exactly sure who I'm supposed to point my finger at, but my point is you shouldn't waste your time on this ONA unless you're the type of person (like me) who plays something in the background while doing work.

The biggest and most obvious issue is the lack of animation in an Original Net Animation. There is nearly no animation other than the mouth. It was so scarce that I was surprised when a character actually walked for a few seconds. I'm honestly convinced that the budget went to the OP and ED. Now, this is obviously not uncommon and sometimes you do get the odd ONA that straight up takes the illustrations from the manga and just colour it in with some VA work done (usually to promote the manga), but we're in the 2020's now and I've seen a large amount of amazingly animated ONAs (The Korean ONA A Day Before Us by Lico comes to mind).
/anime/102425/yeonae-haru-jeon
Furthermore, this manga isn't a small name, it's quite popular which was more surprising that money was spent on translating this to the screen only to be tarnished like this. It's practically the manga but with colour and sound. I might as well just read then (sorry anime only fans). Not everything about this ONA was terrible though; the VA work was quite well done, but I thought that some of the audio quality was slightly off? I found that certain characters were louder than others and some of the sound effects were also louder than some of the characters which I found a little odd. Overall, I was just so stunned by the treatment of this anime that I had to turn to the internet to make sure I wasn't the only one who was surprised and disappointed by this work. As an art student who gets evaluated for animations (above other things), I can tell you that if a student were to hand this in to the professor they would absolutely fail. I'm not sure if my review score would even be an attainable mark if this were to be evaluated. Maybe I'm being too hard on this, but it pains me every time I remember that someone paid for this and this was actually released on Netflix (although Netflix does have its fair share of shockingly horrible content but that's a story for another day).

Now that I'm done ranting about the quality of the actual product, who am I supposed to thank for this mess? Netflix? J.C. Staff? The mangaka? Myself? Well, from my understanding, Netflix basically greenlit this and paid for the manga to be adapted while J.C. Staff was responsible for how this turned out. I'm not sure if the mangaka (and associates) were aware that this was the route that J.C. staff was going with so I don't think I can blame them. I would definitely say that I shouldn't have been as expectant as I should've been because I wouldn't have been so let down. But let's go back to Netflix and J.C. Staff. Unlike their live action shows/movies, I don't think Netflix cares all that much about what goes around with anime as long as they think it'll be popular (evident with Seven Deadly Sins s3*),
/anime/108928/nanatsu-no-taizai-kamigami-no-gekirin
but I think most of the blame has to be on J.C. Staff. Although I can't read kanji, I can certainly read English. Where am I going with this? Well, when you look at the credits, you can see that this anime's been outsourced (any many animes are. I won't tell you whether outsourcing is good or bad when it comes to animation since it really depends on the POV). When you outsource, you're risking the quality of the animation, but this risk really differs depending on the company. Clearly, J.C. Staff wasn't dealt with a good deck, but when you look at their history record, can you say that it was just bad luck? I'm thinking of their more recent works: OPM 2 and the Shokugeki series*.
/anime/97668/one-punch-man-2
/anime/109963/shokugeki-no-souma-shin-no-sara

In the end, all of this is just an individual's opinion and the only way to know if you'll like it or hate it is for you to watch it yourself. Either way, I hope this was helpful in even the slightest bit and if not, I'm sorry for wasting your time. To end it off on a good note, the one thing I really enjoyed were the shorts of the MC's pet cat adventures. It's been a while since I read Gokushufudou, so I can't recall if those shorts were in the manga too. Oh well...

*I haven't watched these, rather they were experiences that I heard second-hand and online.