This anime is one that is considered generic, full of harem and boobs, but from my perspective most of those people didn't even see the anime.
Story:
The story isn't developed. This season is just some kind of introduction, so it has nothing else than the growth of an unknown weak adventurer into a heroe. Still the reason why I give the story a 7 is because this premise is good enough but with no second season it achieves little.
Some of the biggest insults agains this anime is the typical: Generic SAO clone, which this anime isn't if you bother to watch both animes. First, this anime, which is an introduction as I said before achieves the goal of telling the story of an adventurer as an adventurer, not as nothing else. What I mean is that this anime tells you about the adventurer himself, not the plot around him, at least as for this season.
Art
The art was pretty good, I can't really say anything more in this aspect. The fights were also animated awesomely and the characters look good.
Sound: I didn't really paid attention to the sound, but I do know that the anime never had a single time in which the music was bothering. At the same time I can't remember an awesome song, so that's why the 9.
Character:
The characters in themselves weren't developed, aside from Bell, the protagonist which is developed, but not significantly, since the anime is just an intro for a possible next season. I have no problems with the characters being done as they were.
The characters are well drawn, even though some people have issues with Hestia because she has boobs. A problem would be if those were just shown all the time leaning against Bell's face or the camera, but that's not a problem with this anime.
Harem:
The anime doesn't have exactly a harem as most people think of. At the first 2 or so episodes the anime looked like it would be just a harem story, but is quickly abandoned the idea. Yeah, in the later episodes there were some harem-ish situations, but they were just like 3 scenes and a pervert scene.
Overall: Getting this together I think that 8 would be a good score for this anime. The main problem is that this NEEDS a second season or for the viewer to want to read the novels. If there's not second season planned then this will just be a NO for anyone who doesn't plan to read the novels.