I really found this movie to be surprisingly good. It was very enjoyable and heartwarming. Dylan O'Brien's performance was amazing and he was by far the best part of this movie. It did not deviate from telling his character's story and that was a great thing.
Now one more thing; I have arachnophobia so I was expecting some enormous spiders and there was none. So, for that, the coward in me was very disappointed (this is a joke by the way).