It's very likeable. It's a Dungeons & Dragons fantasy series with endearing characters and lots of charm. I'd happily recommend it, especially to anyone who's ever played fantasy tabletop RPGs. However I have some problems with the show that don't damage its charm, but lurk alongside it as things I have to ignore if I want to enjoy it.
Firstly, we have the anime cliches. Well, technically they're light novel adaptation cliches. It's about wish fulfilment. Our hero, Bell Cranell, is a weak-looking nobody with no status. However by the end of the series, he'll have become a hero and super-fighter who's astonished everyone with how quickly he became Super-Awesome! All the girls will be throwing themselves at him, but he's too pure to notice! He forgives everyone. He's Mr Perfect. If you tried to blackmail him into being cruel or mean-spirited, his brain would probably shut down or something.
That said, though, I did like Bell. You can't help but be fond of him. He's terribly nice and he'll work hard to train himself and keep his friends alive. I only got annoyed with him in two scenes where a bad influence tries to make him be lecherous in a way that's not just distasteful, but stupid. Example 1: he's tempted to molest a sleeping woman who also happens to be a near-legendary fighter who could probably kill dragons singlehandedly. She'll have hair-trigger sleeping reflexes. You'd be lucky to live. Example 2: Hermes makes Bell climb a tree to spy on an entire party of female adventurers bathing. They've got enough combined firepower to beat up a god and he's in full view of them. All they have to do is look up. That's practically attempted suicide.
That's only two scenes, though. More fundamentally, I didn't like the harem aspect. Am I getting more intolerant of all that? I'm aware that it's hard to spell out reasons why I should dislike this and not, say, Tenchi Muyo. (I'm talking about early, good Tenchu Muyo, obviously.) However I do have a problem with boys who brush off a girl's confessions of love and behave as if they never happened, for no apparent reason beyond harem formula. That's the genre. All the girls love the hero. It's about fantasy, not human relationships. Presumably the audience isn't meant to be taking it seriously or thinking about it from the girl's point of view... but to me it feels shitty. Talk to her, man! Even if you don't say "yes", at least say something. Don't just behave as if love confessions are an everyday occurrence and not even worth acknowledging. Here we have:
GIRL #1 - Hestia, Bell's goddess. (Yes, she's literally a deity.) Hestia sometimes gets called "Loli-Boob-Goddess" by other characters, suggesting that she represents underage appeal to a certain regrettable segment of the audience, but I don't see it. She's short, yes, but those boobs! She's also an immortal goddess, compared with whom all humans are children. Anyway, Hestia is completely devoted to Bell, drapes herself all over him and wears the skimpiest dress imaginable, even tying a string under her boobs to pull the fabric even tighter. (Amusingly, Hestia's idea of dressing up is far more modest than her normal clothes, since there's no other direction you could go in and still be said to be clothed at all.) When Bell sees the girls bathing, Hestia's only objection is that there were other girls naked besides her.
Hestia is leaving no doubt whatsoever about her feelings for him, openly warning off other girls in front of him, inviting him on dates and so on. She'd be clingy and annoying if it weren't for the fact that she's also super-supportive (even of things and people she personally hates) and a really warm, nice, hard-working person. Hestia's great. She has far better chemistry with Bell than anyone else in the show. They live together and the title sequence shows them getting up, eating breakfast and doing a cute toothbrush wiggle dance.
In other words, Bell's living with an adorable girl who's made it clear that she's in love with him, is coming on super-heavy and is assuming that they're a couple. What does he do to discourage this? Nothing at all. Hmmmm. Admittedly Bell might perhaps feel restrained by his strict ideas about proper human/god relationships, but Hestia doesn't share them.
Hestia/Vestia's from Greek and Roman mythology, by the way. She's of the first Olympian generation and hence is a sibling of Zeus, Demeter, Hades, etc., although she's not mentioned in all lists of the Twelve Olympians. She's the goddess of the hearth, architecture, home, domesticity, family and the state. Here her only worshipper is Bell. There's no mention of the Greek Hestia's vow of perpetual virginity either.
GIRL #2 - Aiz Wallenstein, an adventuress who saves Bell's life at the start of the series. He had a problem with a minotaur. Bell falls for Aiz, but she's so far above him that he thinks she's unattainable and thinks he'll have to train himself up to her level before doing anything. (He's level 1, but she's level 5.) Little does he know that she appears to have feelings for him too.
GIRL #3 - Syr Flover, a waitress who immediately takes a liking to Bell and quite early in the series confesses her love to him. Does Bell react to this either? No. He just goes on with what he'd been talking about.
GIRL #4 - Lilliluka Erde, a "supporter" (i.e. bag-carrier and dogsbody). Lili is actually a really flawed, interesting character who for the most part is immune to harem nonsense. She hates adventurers. For quite a while, she's trying to rip off Bell and sell his equipment for cash. In one episode, she leaves him to die. Even after the hostility's been dialed down, she hardly ever glomps on to Bell and then only, seemingly, as a challenge to Hestia... but even that little isn't entirely comfortable. If Hestia is "Loli-Boob-Goddess", Lili would be Loli-Loli-Loli-Boobs. Hestia looks short, but Lili looks like a ten-year-old. But mysteriously with boobs.
GIRL #5 - Eina Tulle, Bell's manager (?) at the Adventurer's Guild. It's mostly a professional relationship, but she's not beyond seeming to invite Bell on a date too.
...and there are plenty more girls in this world too, although none of those are more than playful and flirty towards Bell. I've mentioned the main ones.
On top of that, we have other kinds of pandering. Some of these cross over with general fantasy tropes, so for instance male adventurers will wear armour and female adventurers will look as if they've just stepped off the beach. There are occasional exceptions, e.g. Aiz's breastplate... but that's a form-fitting, cut-away breastplate with strategic underboob. (In fairness, though, this world also isn't without musclebound Conan-a-likes in just a loincloth.)
We also have some gods who've mysteriously become female, presumably because they heard they were going to be in an anime. Hephaistos, Loki... this isn't one of those anime with no male supporting characters at all, but they're firmly in the minority.
All that's a bit eye-rolling. It's not a critical problem, mind you. This is, after all, a feel-good show where you basically like everyone. Bell is almost childlike in how well-meaning and trusting he is. He's certainly no womaniser. No one ever feels hurt or bad because he appears to be ignoring a lady's advances. The series contains excellent episodes and emotionally engaging stories, with bad things lying in wait for adventurers. (Often these are other adventurers.)
Then we have the problems associated with Dungeons & Dragons.
There's a horrifying moral hole in this series. It's been inherited from Dungeons & Dragons, but I think it stands out more clearly in drama. We all ignore it when we're playing the games. I certainly used to. See an orc, kill an orc! What kind of idiot would see any moral dimension in that?
Personally, though, I found it hard to ignore that this world is built on mass murder. Adventurers kill monsters. That's their working day. No one thinks twice about it. Heigh ho, heigh ho, it's off to hunt down and butcher other races we go! Slaughtering monsters is morally neutral and indeed is seen as heroic, because killing makes you cool, strong and sexy!
Dead monsters leave gems behind, you see. Killing makes you rich! You could argue that it's no different from mining (except that miners don't kill anyone) or butchering animals for food (except that we eat to live and this is just killing to get goods to sell). The nearest real-world equivalent might perhaps be ivory poachers, or perhaps people who kill tigers in order to sell their body parts as ingredients in traditional Chinese medicine. There are still differences, though, including:
(a) The scale and organisation. It's the local economy's main industry. There's an Adventurer's Guild with a front desk and receptionists, to make sure that the ethnic cleansing goes smoothly.
(b) It's not even self-defence. The monsters are all safely corralled in a dungeon. They don't come out. The humans just go in and kill them, after which they respawn like the monsters in a shoot-em-up video game so that the humans can kill them again.
(c) Oh, and in one episode there's a coliseum.
(d) These are fantasy monsters, not tigers and elephants. On the one hand, this makes them more dangerous and the ones we see will all attack you on sight. However what if some or all of them were intelligent? We know that some monsters can cast spells. All you'd need is to hear one monster, just once, say a few words to its friend and this entire show would become a screaming nightmare.
In fairness, these monsters are all dangerous, on a scale that goes from "somewhat" to "very very very". The adventurers are risking their lives. Many of the fights here have Bell and his friends on the back foot, fighting for their lives against insanely strong monsters that are trying very hard to kill them. These fights can be cool and even emotionally powerful. The most powerful monster we see (i.e. the Goliath) is basically a Titan from Attack on Titan, except even more nightmarish because of its magical superpowers. Also, obviously, it's unfair for me to pick only on this anime when you could say similar things of thousands of other fantasy games, films, books and TV shows. However I still see it as disturbing. When Bell gains a magic spell, he tests this by going on a random killing spree.
If I were a monster in this universe, I'd want to murder humans too. (Oh, and I liked the killer albino rabbits.) Apart from all that, though, I found this show interesting and charming.
The setting is interesting, both as a spin on and a literal realisation of gaming tropes. Adventurers are Level 1, Level 2, etc. They also have stats written on their bodies. You can read them and know someone's strength, agility, etc. However they're tattooed magically on your back, so you can't actually see your own stats unless someone else tells you.
The Adventurer's Guild is an interesting bit of worldbuilding, with every adventurer having a personal adviser. The gods living on Earth among their worshippers is an intriguing idea, even if for the sake of game balance they've agreed to seal away most of their powers and not go into dungeons. I also like the often nasty portrayal of party dynamics. Porters get treated like dirt, while parties are more than willing to save their necks by dumping a load of monsters on a rival party in mid-dungeon.
The show's best material tends to involve dungeoneering. Bell does a fair bit of solo dungeon-crawling, but he gradually builds up a small party who go dungeoneering and get into insanely bad trouble together. Life-or-death danger is compelling. Those character relationships feel more real and meaningful than the fluffy stuff outside the dungeon (fun though that is too), with Bell's forgiveness of Lili being a big deal given everything she did to him. I also really liked Welf Crozzo, partly because he's male and hence doesn't have a crush on Bell. It's so refreshing to get a break from all that.
Apparently the show races through the original light novels. One of them (vol.4) even gets adapted as a single episode (ep.9). Speaking as someone who hasn't read those novels, I thought the anime's pacing was fine.
It's a show to give you warm fuzzies. Bell is a sweetie pie and Hestia is adorable. It's a world full of thoroughly nice people, in fact, although the flip side of that is that the occasional bullies we meet are cartoonish and panto-like. I enjoyed this show and I find its characterisation is effective, but it does tend to be painted in bright primary colours. Fortunately there are also exceptions to this, e.g. Lili or Ryuu Lion. They give us some genuinely strong episodes, like ep.6 and ep.12. I'd recommend this show to almost anyone, especially if you used to play Dungeons & Dragons. It's just that I was having to squint past the fundamentals of the show's genre and worldbuilding.