I took time to reflect on this drama and the more i thiught about it, the more i found things that i disliked.
I'm going to start with the thing i liked, the ML, i always liked him and this role was quite fitting to him. The moments he had with his girlfriend were all super cute.
The FL, looked bland to me, don't get me wrong, she is a good actor but she lacked alchemy with the ML. Although the scenes they had together were cute, the alchemy wasn't here.
Other than that, the plot was quite good but pretty much flawed:
One thing is the fantasy Link they have between them. It was badly executed, i had to make an explanation for myself because their explanation wasnt making sense. I wish they didnt explain it and jusy left it there, it could be like an ability or a super power or something.
Second thing, is the lack of motive. Its a crime solving kind of drama but there were no reason to explain that said crime. The criminal had no motive. He just killed people. They didnt say how many, if he was a serial killer, why did he do it.
Third thing, is the FL didnt even TRY to protect herself. This drama started with the first episode of her getting almost killed by her stalker but throughout the entire 16 episode she walked alone at night like people werent waiting to kill her, going to strange places by herself without saying it to anyone, reaching her stalker.... Half of the thing that happened were avoidable if she had been cautious.

I think that the romance part of the drama was more well written than the crime/thriller part beacuse it was only thrilling because she made poor choices. However despite all of this I'd say this drama was entertaining. I would recommend it.