It's another isekai. Ridiculously overpowered teenagers get summoned to a fantasy world to play games. The plot's fairly standard. Nothing wrong with it, but it's nothing you need to run out and watch right now. No Game No Life is a better version of the same premise, i.e. a fantasy world where games rule everything and a brilliant game-player can enslave or destroy entire communities.
What makes this slightly different are the teenagers themselves. As the title suggests, they're problem children. They're badly behaved, full of attitude and guaranteed to make trouble for their supposed allies. Also, they already had their superpowers even in their original worlds. There are three of them:
IZAYOI SAKAMAKI (m) = by far the most arrogant, violent and overpowered Problem Child. He kicks a god dragon in the head in ep.1. He's also the kind of person who'll deal with bullies by chucking bombs at them (and their victim). For laughs. Oh, and he's super-intelligent. He'd kill the show's drama if he was a regular hero, but fortunately he's a pain in the arse who drives his allies (well, Black Rabbit) as crazy as he does his enemies.
ASUKA KUDOU (f) = has the Word of God, like Jesse Custer in Garth Ennis's Preacher (but even more powerful). She can command people, animals and even plants. She can't fight physically like the other two Problem Children, but who cares? She's also rich, privileged and talks as if she's the queen.
YOU KASUKABE (f) = quiet, unobtrusive, can speak to animals and absorb their physical abilities. In time, she becomes a fighter nearly on Izayoi's level. It's possible that the others are a bad influence on her, given how enthusiastically she joins in with their bad behaviour. (She never stops being impassive, though.)
The storyline's fine, if a bit episodic. Game, game, game, end. Black Rabbit summons the Problem Children to help her once-powerful community regain its place in the world. They'll defeat some nasty baddies, although the show's tone is too light to make them as horrifying as they could have been. One chap makes a habit of kidnapping children to force other communities to do as he wants, without telling anyone that he always kills his hostages immediately. He just doesn't like kids. There's also an embodiment of the Black Death.
The cast are, similarly, fine. They're not particularly dramatic, obviously. Nothing can slow down Izayoi and they're only doing it all for laughs anyway. However they're reasonably entertaining. Asuka even gets some character development, befriending a little fairy creature from the Pied Piper of Hamelyn's world and becoming significantly nicer.
There's also a cool theme song.
I don't know if I'd call this a good show, but it's perfectly okay. I quite liked it. It's a renter rather than a keeper, but it was entertaining. The only thing I disliked was Black Rabbit saying "yes" in English, which jars with the rest of her speech pattern. It's cool, light-hearted and sometimes funny. Ep.5 has a nifty humiliation of an overweeningly arrogant baddie, while the OVA is self-aware fanservice. You could do worse.