Awwww! What a cute movie! To be honest, I don't think I can really mention anything that needs improving for it to achieve its goal. The acting, writing, cinematography and script are all perfect for a romantic movie like this, and I think I'd go as far as saying it's the best romance flick I've ever seen (although I'll be the first to admit that I haven't seen many).
One small problem that I saw was that the transition to the ending seemed to happen a little too fast, but then making it any longer probably wouldn't have been an improvement considering how perfect the 2 hour running time felt. I think just distributing some hints earlier on might have helped. Still, it's nothing major, and the ending is still quite touching.
In a sentence:
An awesome, happy, light and cute little movie that is perfect for couples and that is probably the best non-comedy romance movie I've seen.