This film has everything to enjoy - from a potential-packed storyline and beautiful OSTs to a talented cast and sparse comedic relief, it's exactly what a dystopian action film should be. I was honestly worried that it wouldn't be good as a stand-alone film due to it being promotion for P1Harmony, but you could definitely watch it and enjoy it even if you aren't interested in them! I do suggest rewatching it, though: during my first viewing, it was hard to keep track of the storyline, but it was much more enjoyable the second time because I knew the outline of what happened and could therefore pay attention to implications and detials. I especially liked how this film felt like an introduction to the world P1Harmony's concept is from, and how it was more implicit than explicit, allowing the audience to form their own opinions and theories. I definitely think this is one to watch, and I look forward to future continuations of the series!