This series generated quite a lot of expectations when it was announced that Jimmy and Tommy will act along Korean actors in a Korean-Thai co-production filmed in Korea.

The show has some strong points:

1) Good chemistry: Jimmy and Tommy have acted together in "Why R U" and have been a BL "couple" ever since... so we knew they have good chemistry. Their main issue was the challenge of going to Korea to film alongside Korean actors and get used to the Korean way of doing dramas. They talked about it in several videos you can find on Youtube and overall I think they did a very decent job. And yes, I know Jimmy's acting skills still need to improve, especially in the sad/dramatic scenes, but I felt he provided very nice moments throughout the series. In addition, his chemistry with Korean actor Choi Jae-hyun was not perfect but it was quite good despite Jae-hyun being 5 years older than Jimmy and having quite a bit more acting experience.
Both play their roles effectively and convincingly enough. And while other Korean BL series have had better chemistry among the lead actors (see "To My Star", "Where Your Eyes Linger" and "Mr. Heart" for examples) both actors navigated through the language barrier to present a very decent product.

2) The music: This was one of the best parts of the series. The OST is nice and all the music surrounding some of the scenes was always on point and even complemented the weather and the mood on the scene.

Now some of the not so strong points:

1) Plot: The story of someone being able to see a ghost is not new (see Thailand's very good "He's Coming to Me" with Singto and Ohm Pawat and the 2 episodes dedicated to the Thurs-Pao/Pae story in the disaster that was "Y-Destiny" for examples) but the story of Yoon-oh and Peach brought the added fact that Yoon-oh could not leave for the afterlife because he had a deep sorrow to solve. Despite what the preview mentioned about Yoon-oh and his mother being a bit distant, I always wondered about the "real" sorrow that Yoon-oh could have... was it a) his relationship with his mother, b) his feelings for Peach, c) the cause of his death, d) a combination of all of the above?
The first episodes were clearly focused on his relationship with his mother because Yoon-oh seemed to be hindering some anger or resentment towards her. Then, when Mario starts meddling in the Yoon-oh/Peach relationship, we see some hints of Yoon-oh being sad or regretful about loving Peach but not being able to remain with him forever. Then, near the end of the series, the issue of Yoon-oh's death is brought to the center with suicide being ruled out thanks to new footage from another car's dashcam. We also get very few details of Yoon-oh's visit to Phuket so we assume they fell in love with each other there but never had the chance to develop those feelings with Yoon-oh returning to Korea and Peach going to Africa for charity work.
The problem with all of these scenarios is that the plot never really focuses on one aspect alone and works on it to develop it in a more satisfying way. They jumped from the mother-son relationship, to the Yoon-oh/Peach relationship, to even involving the man trying to sue Yoon-oh's mother for malpractice as being the one who caused Yoon-oh to step into traffic and be killed (which is a weak argument as the man never pushed him or forced him to start walking on the street) and then, all is magically resolved in the final half of episode 10.

2) Support actors: Tommy, the girl who helps Peach in the café (Shin-ji) and the girl's mother (Soo-jin) are all connected as Tommy's character, Mario, also has a deep sorrow that he couldn't solve in many many years, but ends up being solved in about 3 episodes of the series. He worked at the resort and fell in love with Soo-jin but then died on a fire without being able to see her. His sorrow was that he never knew why she didn't show up... we find the reason around episode 8 and that was it, nothing very significant.
Yoon-oh's mother and the man who is trying to sue her have some intense interactions as he blames her for his daughter being in a coma but she proves to him that it was not her fault. But, as the lead surgeon on duty and with the hospital trying to prevent a scandal that will generate bad reputation, she tries to hide the incident at first but then takes responsibility for it. The hospital director is just a crook who only thinks about the economic aspect and the hospital's reputation with a possible lawsuit instead of anything else and the 2 cops who investigate Yoon-oh's death are probably the worst cops in Korea by doing a very very poor investigation of the case.
Of all the characters, Mario and Yoon-oh's mother should be the 2 most important ones but he gets lost a bit thanks to a weak plot/scenario for his character and Yoon-oh's mother gets involved with the possible lawsuit and the hospital way more than she should. I mean, Peach tells her he can see and interact with Yoon-oh, she faints when Peach proves it by talking about the cat she adopted and then gave away because of her allergies and then, nothing... that topic is not touched again until the Christmas party when Yoon-oh sings on episode 10 and Peach tells her he is singing in front of her.

3) The finale: I get Yoon-oh had to leave but we never get the real reason of his deep sorrow, which is why I think it might have been a combination of all the 3 options I mentioned above. In the end, he just says "I love you" to Peach and without any goodbye, he just vanishes in thin air before being able to kiss Peach (for the third time on the series). Then, when Peach is in the now closed café, the kettle starts boiling out of nowhere which might signal that Yoon-oh came back or actually never left in the first place, but we never get a clear answer. The finale was a bit disappointing as big chunks of the last part of the episode were spent with Yoon-oh singing the same song twice, first at the party and later in front of the sea with Jimmy looking like he was about to freeze (they filmed in winter and both Jimmy and Tommy being from Thailand had to deal with snow and cold temperatures, something both were not very used to).

The movie version should come out at some point in 2022 and, if they follow all the previous Korean BL dramas, it will usually include a bit more scenes that were not included in the regular episodes due to time constraints. Hopefully, we get an extra scene with a bit more than just the kettle boiling, otherwise the finale will remain a bit disappointing.

In the end, the series had nice moments and I'm sure Jimmy and Tommy faced challenges when dealing with dialogues in Thai and Korean and also having to adapt to a mostly Korean production. Filming in a foreign country without dominating the language is always hard and it takes a lot of courage to do it. Sadly, the end product was just good but not great.