A little unfocused, could have done with better editing and story-telling and even better leads. Well, actually I wasn't crazy about Miao Miao at all. I couldn't really warm up to her or root for her, she was too aloof and charmless and her sudden crush makes no sense, maybe it's my adult mind, but really there's no need to be so heartbroken over a guy who barely notices you're alive. And Ai and Miao Miao's dynamic is very strong in the beginning but then takes second place, that why I'm saying some better editing would have helped maybe. Chen Fei's trauma surrounding Bei could also have benefitted from better story-telling as I was pretty unsure of what was happening with them and when. He himself articulates it towards the end so that clears things up. Anyway, better stay away from Fei types. The likes of him only look good from afar.
All in all I felt the first love, first heartbreak type of conclusion was kind of forced, but I am sure plenty of people find it charming and it's rather short so why not... Also, time capsule of the 2000s. Those haircuts...
Again, the poster is not in the movie.