No Game No Life is one of those shows that I added to my playlist based on premise, rather than someone's recommendation or previous work by the creators. Doing that is a gamble, and this one turned out to be a loser.
Sora and Shiro are constantly getting into situations where they should lose their games, but then it turns out they foresaw the situation and pull out some amazing table-turning victory. The explanation always boils down to "Sora and Shiro together are smarter than everyone else." In almost every episode there's some new twist on it, but it always comes down to the same thing in the end.
I expected the show to either try to explain things seriously, or make everything a joke. Either approach could make for good entertainment, but the writers chose to attempt both. Most of an episode will seem to be seriously trying to explain what's happening in the game-of-the-week, but suddenly out of the blue there will be a couple minutes where everything is a big joke. Worse, they also added a whole lot of stereotypical harem-style fan service aspects. The funny stuff mostly revolves around humiliating Steph in various ways, mostly involving scanty outfits. Didn't seem very funny to me.
I've put up with similar problems in other shows before if the characters are well-formed and change over time in interesting ways, but No Game No Life doesn't manage that, either. Sora is a arrogant jerk, and since he's always the smartest guy in the room (except maybe his sister) there's no reason to change. Shiro has basically no personality at all and is totally dependent on Sora. The other characters are around only as comic-relief targets or enemies to be conquered.
Had No Game No Life been any longer than 12 episodes, I'd never have finished it. As it is, I stuck it out to the end, in hopes that it might improve by the end. No such luck. This is one to avoid.