As I finished the current three season, I was really satisfied. I gave this show a 5 out of 5 was because due to it's overall quality, this show was entertaining and sometimes even thrilling.
The graphic and animation was vivid. It perfectly upgraded the style in the original graphic novel by Luke Pearson. Of course, as all the original story setting, plotline and designs were made by him, I gave him praise and applauses.
It overall gave me a light touch; a sort of peaceful feeling as some episode goes with it's beautiful music in the background, but also left me cliffhanger in some episode, like when Hilda was turned into a troll with her mother angry and worried about not knowing where she is it happened so surprisingly that I felt the urge to watch more. The point is that it got interesting plot twists that can be burp out as a surprise.
I have nothing a lot to talk about the voice acting, although Alfur really made me wondered if he's a girl or a boy as his voice could have been easily both, but otherwise the voices suits most of the characters pretty well.
I like the characters as they feel just comfortable to me with their own characteristics. Woodman might be a good example. He was unique with a sort of interesting personality that the voice acting made him even more likeable.
However, there is one thing that can be said as a flaw. I that found some of the episodes wasn't as interesting. Well, more specifically is that it feel bland compare to the some other brilliant parts, but it still didn't really effect the overall experience.