It wasn't easy to make this review unbiased considering I'm a huge fan of Attack on Titan, so please bear that in mind as you read it.
I just finished watching this after finally getting round to it and honestly, I found it to be really entertaining. Not entertaining in the same way that a really interesting series is, but entertaining in a way that had me wondering what funny antics they'd get up to next. This had me watching the whole thing without taking a break, which says a lot about how much I actually enjoyed it. Usually I can't stand chibi-style characters or spinoff series but I love the characters from Attack on Titan so much that I figured I should give it a try, and I got pretty much everything I bargained for.
I'm a little surprised it has such low average ratings if I'm honest, because to me it was everything it was set out to be: domestic, cute, entertaining, and funny. It seemed like a really nice break from the carnage and horror of the actual show, a little like the Junior High spinoff series. Obviously it doesn't deserve all that much credit because it doesn't have the same kind of interesting plot or character development as the show does, and that's not to mention the strange animation, but I still found it very pleasant to watch. I'm only giving the "plot" a low rating because there isn't really a plot at all, but that's to be expected considering it's just a bunch of cute shorts. Don't come looking for a good story if you watch this because it's not a story - each episode stands alone.
As for the characters, I suppose I can't rate those fairly either because I'm already a huge fan of the characters from Attack on Titan, so naturally I'd feel inclined to give it a high rating. But to me I feel like they could have included the characters in a more diverse proportion considering some didn't actually show up until towards the final episode. Other than that, though, I don't have many complaints. Everyone was very in-character and this surprised me - animation aside, they were almost exactly how they are in the canon series, and I think that's a pretty great feature considering the vast difference between the genres. It was impressive to me that their personalities were almost identical to what you'd expect whilst still managing to be funny and entertaining.
I didn't like the character animation but I suppose that's more of a personal preference than anything. The chibi-style characters did fit quite well with the genre and all, but something about it didn't sit right with me. It seemed too cartoonish for something based on such a brilliantly depressing show. I personally think it would have been a lot better with a style closer to that of the one used in Junior High: still cute and cartoonish, but not overly so, and a lot easier on the eyes. Something about it seemed slightly unprofessional in a way and it would have been a lot more enjoyable if it went lighter on the chibi art style. The animation of the settings was perfectly fine though, and was a lot simpler than that of the main series, which suited the lighthearted nature of the show very well.
Just like with the characters, I can't exactly make a fair comment on the soundtrack because it's exactly the same as that in the real show (as far as I could tell). So naturally I'll be giving it a high rating because I like the soundtrack from Attack on Titan. I do think it seemed just a little unfitting for this series though, and I think that it would have been better if they'd used OSTs that were based on the originals but altered slightly to give off a more lighthearted and comedic vibe.
On the whole, though, definitely not bad considering what it sets out to be. In my view it's only worth watching if you're really obsessed with the series like I am, because otherwise you'll probably find it a little boring. It's not even what I'd consider to be impressive but, somehow, it did something for me, despite coming across as if there wasn't much thought put into it at all. I don't know how it managed to be good but it actually did.