Goblin Slayer is kinda entertaining. It's not entertaining because it has a compelling plot, or any deep themes, or any multi-faceted characters (dear god no). Characters have such stupendously little depth that most of them don't even have proper names. That is not a joke. The four important main characters outside of the protagonist are referred to as "Elf", "Dwarf", "Guild Girl", and "Lizardman". Check the wiki if you don't believe me.

The world-building is pretty questionable. The premise is a generic RPG fantasy world except goblins are much more vile and dangerous than usual. They wreak havoc every day by pillaging villages and raping women. Beginner adventurers attempt to kill the goblins, but many (most?) of them perish in their attempts due to their inexperience and get raped and plundered and murdered. But there are apparently worse problems in the world (problems that are never actually elaborated on) and goblins are too weak to be thought of as a "real threat" (even though they very clearly are not weak, as high-level adventurers are shown to have trouble with goblin hordes in later chapters), so quests to slay goblins grant very little reward. This remains the case even with important quests that involve the protection of entire defenseless villages from goblin attacks. Because of the disproportionately small pay, no one actually competent bothers to help out, so as a result normal citizens, beginner adventurers, and entire villages get destroyed by goblins practically on a daily basis. But apparently it's no big deal, so goblin extermination quests still have low rewards. Nothing makes sense, but whatever, fuck it.

Insert our badass protagonist, the fabled Goblin Slayer, whom bards sing of and people fear. He has made it quite clear many a time that his entire purpose in life is to kill goblins. He flat-out refuses to accept any quest unrelated to murdering goblins - he lives for it and knows everything about the goblin hunt, from how they eat to how they move. He has plenty of experience destroying goblin nests and doesn't flinch in killing even the youngest. He reasons that baby goblins that are spared by adventurers become truly strong when they grow up. So he crushes them (most of the time literally).

That's it. This dude kills hoards of goblins because of his "tragic past" involving them (a past he suddenly elaborated about without ever being asked early on in the manga.. talk about subtlety). And women love him. Nearly every female character he meets lusts for him. How could women not love him? He's the best goblin slayer around.

How about the other characters? Well, as I had mentioned earlier, most of them don't even have proper names. All of the women only exist to fall in love with the protagonist to make him look cool. I don't really remember any male characters aside from the nameless generic dwarf dude and the lizard whose sole personality trait is eating cheese.

So why is it entertaining? Well... it's honestly pretty fun, despite it all. The goblin slaying is often done in creative ways, and the protagonist comes up with half-way interesting plans in destroying the things. It's also enjoyable in just how brutal he is at times. At some point, I genuinely wondered why the author was so fixated on vilifying and destroying goblins. Did a goblin murder his family? Did he read a doujin with them and his favorite female character? Does he just not like the way they look?

In all, I give Goblin Slayer a 6/10, which is pretty damn generous given the many negative aspects of it. A more objective and fair rating would be a 2/10 or something, but I don't really care. Sure, it may not be very intellectually stimulating, but it's far more enjoyable than other "turn your brain off to enjoy" manga like most battle shonen because the author of Goblin Slayer realizes the only entertaining aspect of these things is the ridiculous fighting scenes. It's actually genuinely inspiring how little the author gives a fuck when it comes to world-building, character development, thought-provoking themes, or anything that would normally be prevalent in such a tragic, character-driven story. It doesn't feign a stupid facade of depth. There's no protagonist I want to strangle, there's no stupid "friendship is power" monologues and no real coherent plot whatsoever. It's a manga about a badass and his genocide against goblins and I like it.