Like Sherlock Holmes's dog that barked in the night, it's interesting because of what didn't happen. It's an anime adaptation of a mobile phone game, in which a male isekai protagonist with mysterious hidden powers gets surrounded by girls with big boobs. This is a fantasy RPG world. There will be monsters, but they're not very important and the series doesn't really have much in the way of a story. It's mostly just girls goofing off in disposable filler episodes.

There are dozens of shows like this. You can hardly move for them. This one, though, was a massive hit, even though the game it's based on was actually a sequel to another game that only lasted about a year.

Its secret ingredient, I think, is how it embraces the shallowness of its source material. Its writer/director (Takaomi Kanasaki) had previously worked on KonoSuba, which at least in some episodes had been paying homage to old-school children's anime. This show does the same, but does a better job of being a children's show. Nothing much matters. All the main characters are likeable, even the grumpy tsundere. The visuals are flat, cheap and unimpressive, but they're full of energy and the body language is jolly and broad. (KonoSuba is a far funnier, sharper series, but it can also be sleazy, e.g. the episode where Kazuma mistakes Darkness for a succubus he's hired.)

Similarly, the male isekai hero isn't being set up as the audience identification character. He's barely sentient. He's got amnesia and he just hangs out uncomprehendingly with the girls like a big, friendly dog. Furthermore, no one's romantically interested in him. Kokkoro is attached to him, but he'd be dead if she weren't. She's his minder.

The monsters and baddies are deliberately rubbish. I hated ep.1, with those goggle-eyed dogs and those two Comedy Bandits. (They become regular characters and the show forgets that they were thieves.) There's a squid that says "squid". Sometimes it's the voice actor who's off, so for instance I found Chiaki Takahashi's deep voice unconvincing as Christina. Whenever our heroes fight a monster, expect it to look stupid. That's the show's style. That said, though, the Shadows don't look silly and the giant one in ep.12 is a "holy shit" opponent. (The show's bent its rules for a more dramatic finale.)

The boobs and outfits would be outrageous fanservice in a less cartoonish series. Guess what. (That said, though, I've just googled "Princess Connect! Re:Dive cosplay" and most of the outfits are rather good, being sensible and well designed.)

Ep.12 has a badass monster and ep.13 creates dramatic backstory for Pecorine, which are both good but atypical for the series. Until then, though, it's just a happy, friendly show that doesn't really mean much. It's easy to watch. I was happy to watch it, but I'd struggle to remember what happened in most of the episodes. The sinister hospital with the bloody handprints was quite fun (ep.5). The cutesy-but-spitting llama was amusing. The regular cast are perfectly okay, with Pecorine being a happy beam of sunshine and also Superman with boobs. Meanwhile, Kyarl is a grumpy cat-girl who disapproves of everything and was originally supposed to assassinate Pecorine, so was aghast to find herself being befriended instead. She's the show's most reliable source of comedy. Her teammates cook and serve up bugs, for instance. Her opinion of this is what you're imagining.

As I said, this show was a hit and it got a second season in 2022. I watched that too, but without being convinced that the show had legs. Like a lesser Kemono Friends, I think it's coasting on charm and it's not as good underneath as you'd think from the reviews. Its schtick is basically to be goofy and a bit rubbish, e.g. swords in fights don't behave like sharp instruments. That said, though, it's fascinating to compare Takaomi Kanasaki's show with the by-the-numbers isekai genre material he was given. It's an interesting experiment. I approve of it. Sometimes it made me laugh.