I was really excited to watch this series knowing that it was an adaptation of a popular UK series. I always look forward as to how kdrama writers will interpret it to the k-viewers liking.
This one definitely gave me the INCEPTION vibes which I really wasn't expecting at all however I can't help but to compare this to other dramas which also had similar concepts such as TUNNEL and SIGNAL, both had time travel fantasy twist, both are crime detective series chasing serial killers and both occurred in the year 1988. I just wonder what special connection do Koreans have with the 80's(insert REPLY 1988 and the movies 1987 and a taxi driver).

pros
1. the attention to details. One thing I always look forward to in time travel dramas is the set production. Compared to reply 1988 (which also gave us incredible detailed props and styling) this drama is obviously at a much larger scale where they filmed at busy streets and open spaces which required a lot of people, cars/transportations, building, malls and night club and they did a great job with it

2. the cinematography gave us retro vibes, it really took us to the 80's and I especially love the mood lighting in the bar where they always hang out. the use of colors and hues during the night time scenes were incredible

3. each of the cases felt real and raw. it wasn't the most original but the way it was done felt really authentic

4. that mini bonding with his younger self was just adorable. I believe most of us would love that opportunity to talk to our younger selves as well


cons
1. Jung Kyung ho. I wasn't sure about him playing the lead role (I haven't seen the US version though) His character seemed to be timid and plain

2. Park Sung Woong. a lot of the time he was overly aggressive, violent and obnoxious

3. that other cop who have curly hair was being a jerk and annoying as hell as well

4. the time travel transition wasn't smooth. Let's admit it, the "time travel" scene is the most awaited part of any time travel drama because it simply highlights the whole point of the story but I was underwhelmed watching it here

5. I wasn't buying the bromance

6. while I appreciate the writers for putting in humor, a lot of times the comedy parts fell flat

7. detective/police dramas are all about the ensemble and the chemistry among them but this cast wasn't the strongest TBH

8. too much filler episodes. I'd rather watch a 10-12 episode drama with a solid focus point than something with 16 or more episodes that have too much loopholes and detours and beating round the bush

9. the episode where he had a reunion with his family was supposed to be heartbreaking, if it was me I would've lost it and broke down however he only had his poker face the entire time. I had the same problem with his reaction when he first realized that he's in the year 1988, was it the actor's fault or the director's?

10. things only started to build up during the second half of the series and even then there's still a lot of filler episodes

11. the ending was a total drag that they could've totally scrapped the entire episode and end it in episode 15 instead.
I believe that tae Joon shouldn't stay in 1988 because two tae joons cannot exist in one lifetime (things that I learned from tomorrow with you)

It's definitely a decent drama at the end of the day, it had all the right makings of a great detective series. But personally I still think TUNNEL, SIGNAL and even CIRCLE and DUEL were much stronger crime/detective dramas over all compared to this.