[Mild spoilers ahead]

I haven't watched the original movie but I suppose this one is build up on the same plot skeleton as that one.

We all want to know what the future holds for us. Maybe show us a direction?
But knowing what happens in the future isn't always the best. Sometimes being ignorant and in the moment seems better. Sometimes knowing it makes us take steps we wouldn't have otherwise.
And this movie is all about this!

I personally liked how this movie was executed as well as the plot. Let me explain why!

This does differ from most of the time travel ones as they usually let go of a character or somehow make them end up together.
I do agree that the pace could be slowed down to an extent as it feels rushed but leaving that aside, this was a beautiful watch.
This felt a little realistic to me (imo).
Knowing the future doesn't always end in a good way. Maybe Kim Yong would have had a different ending if not for these interactions but he would have had to give up on his dreams for love. He might have regretted this love latter in life(A lot of people just want a happy ending here but yall are avoiding a lot of real problems here) . And the love the both experienced wouldn't have lasted for long because if he indeed trusted his gf, he wouldn't have been paranoid and jealous of his bestfriend whom he has known for years. He himself also felt like this was for the best...the turtle scene shows it all. He knew he couldn't change the ending and decided to just accept it. He also really liked(not romantically) Mun Nee enough to sacrifice it all. She showed him a way when he felt stuck. He wasn't happy with the course and just continued for love. Mun nee was a miracle to him and so was he to her. She showed him a direction and he wanted to do the same for her. It's clear from what he says at the end to her and him returning the favor to her through the umbrella scene.
This was beautiful. Too many ways to interpret it.

Its a good one time watch which makes you think a little and makes you appreciate being in the moment and ignorant of the future sometimes.

Maybe he would have had a different ending if they wouldn't have connected or maybe the ending would just have been the same except a different path? We would never know!

Also this gives out huge grandfather paradox vibes and I love it