This series delivers on all fronts - time travel, body-swaps, romance, love-triangle, friendships and comedy. This is testament to the to plot and actors. I am not surprised there will be a Korean remake, given its widespread acclaim.

The good
Compared to big budget k-dramas it feels a lot more indie and subtle. Straightaway the intro gives off these vibes. Rather than this being a limiting factor, it actually helps deliver the fantasy plot-line. The cast and locations quickly feel authentic and familiar. The OST isn't overbearing and you will definitely either learn to love or hate Wu Bai's Last Dance!
The pacing keeps you invested with plenty of twists along the way. After the first couple of episodes I was hooked.
One of the best romances I have seen in a series. It's very much an insight into a relationship rather than just intimacy.
The two leads are very good. Alice Ko convincingly plays two different characters and captures the pain of losing someone you love. Greg Hsu delivers as leading man material who is both the carefree teenager and jaded adult.
The ending is bittersweet but falls on the sweet end of the spectrum.

The bad
Very little. If I had to nitpick, I found that the immediate willingness of the Uncle to believe in time travel was unrealistic. Although this was probably necessary to move the plot forward. It's also apparent that the budget was a limiting factor. The scenes where Chen Yun-Ru is stuck inside Huang Yu-Hsuan head do feel a little like a school theatre production. Lastly, the plot can get confusing so I would recommend using Google to recap each episode if you are unsure.

In summary, well worth a watch.