It could be just me but I personally found the story sweet and inspiring. The story of a golf star found his way to redeem himself through teaching kids on a small island is heartwarming. I don't think that a good movie needs to have a complicated plot or dashing effects. This movie is simple and meaningful. There are some comedies here and there. The acting is really good. I don't think it is easy playing a mute person because it would require more facial expressions. Yoon Shi Yoon definitely nailed it. Jin Goo also did well. Not sure if this is his debut work or not but I was impressed with his acting as well. Whether you are a fan or not, you should give this movie a shot. If you are a YSY or JG fan, you should definitely watch this. They look extra good here. The music matches the theme of the movie well. Unrelated but the father character is the bakery owner/chef in YSY's former drama King of Baking, Kim Tak Goo.
I am attaching the links for this movie in this review since many ppl in the comments seem to have a hard time finding this movie with eng sub. There are 2 parts betw
https://www.dailymotion.com/video/x6svo2q
https://www.dailymotion.com/video/x6svo2r