"How to Train Your Dragon 2" remains to be one of 2014's biggest movies. But despite the blockbuster success, there are some people who didn't like the movie.

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Some suggest that the marketing for the film is to blame. But, many (most especially parents) think it has something to do with the sequel's plot twist.

In "How To Train Your Dragon 2" Hiccup's mother resurfaced, exposing a whole new world of dragons she discovered. Consequently, Toothless was mind controlled by the antagonist and unfortunately killed Hiccup's father, Stoick.

It seemed like a harmless plot twist, but parents are not that glad to see one of the protagonist's parent killed off. As some parents shared in commonsensemedia.com, a website that allows users to review movies, the film was disappointing most especially to their children.

"There were no fewer than 8 little kids crying at the VERY sad parts (a significant and central character is killed off ... Unnecessarily IMHO). The character doesn't just die but is killed by a beloved central character under mind control. The movie is well written but very poignant and full of sad moments and a few frightening scenes, including a close up of a Viking body about to go up in flames on a funeral boat. I did not enjoy it because of this waste of a fabulous character. I don't take my kids to movies to feel sad and morose. my boys,12 and 9, thought the movie was "okay. The fighting scenes and dragon scenes were cool." Disappointed," one parent shared.

"We were disappointed as this movie is very intense and sad. My son cried very hard twice during the movie - once during the fighting scene because he was scared. The scenes aren't graphic, but the music and emotion behind them is very strong. He cried again very hard when a main character dies. ... My son said he never wants to see this movie again because he was too scared and too sad," another parent said.

WATCH "HOW TO TRAIN YOUR DRAGON 2" FULL MOVIE.