This movie markets itself as the story of "Love, Chunibyo, and Other Delusions" but through the eyes (eye) of the series' heroine, Rikka Takanashi. For fans of the series, they may hear this concept like I did and think the following:
"Oh, that sounds awesome! We can see things we've never seen before in the story and see multiple moments from the series remade to be more fantastical and unrealistic to fit into Rikka's Chunibyo."
But instead of doing something cool like that, this movie is just the bare basics of the "Love, Chunibiyo" story to be counted as a recap. Like a cake without any of the frosting or the flavoring. Honestly outside of a admittedly really great opening scene and a new ending scene, this movie has nothing of worth to offer. This movie for 95% of itself, doesn't have the soul of the original series and that is obvious with the story obviously feeling like just a random splicing of scenes from the show together that you could find on youtube.
I don't get how this movie has such a high rating, this movie is "Love, Chunibyo" without any of the charm or love the main series and sequel film have. So it doesn't even work as an entry point for new fans.
In the end, skip this movie. Just watch season 1 of the show, then look up the opening scene and ending scene of the movie on youtube and watch that. Then watch season 2, and then the Take on Me Movie because they are really good also. Besides that also check out the shorts, because they are also better then this movie. And boom, you did it! You just saved your self an hour of your time.