About the voice acting, at first, I didn't like how Hiccup's sound is like. Not a hero-type. However, after getting into the story, I realized that it is on purpose. And the voice acting is how all the humors are presented. The sarcastic conversations are the funniest.Actually it seems that the sarcasm is one of remarkable features of animations by DreamWork. Speaking of DW, you cannot forget Shrek. That make sense now. Hiccup is just like Shrek, but tinier.
the story is a cliche, not much surprise. The excellent part is the characters and the relationship between them. Each characters has his/her unique features which make him/her memorable. Hiccup is kind of whinny, while Astrid (the blonde) is aggressive. And Toothless is wit like a cat. (somehow I think Toothless IS a cat in flying reptile form.) There are geek-like character (the fat) and the bully guy. The most interesting scenario is the part that Hiccup and toothless built up their friendship.