There's a lot of comparison between Signal and Tunnel for being both crime dramas. I think the female lead in Tunnel is slightly stronger, in how she was written, although I am undecided if I like her or not. Male lead in Signal was less frustrating to watch. Signal was a better-written show. Both executed very well with strong music. Ultimately, though, I would recommend Signal to my friends over this show. Watch this if you're in the mood for a crime drama. The first half are more procedural and more enjoyable to watch, as the second half is focused on wrapping up the major storyline. Unfortunately, this drama doesn't make it to the top of my list for the following reasons: - Lack of logic in dialogue. Many moments where I'm scratching my head wondering why people aren't more suspicious. - Why do they never wear gloves at the crime scenes? - Some parts were not fully explained and one supporting character dropped off the show with little explanation. - Some of the "reveal" scenes made me laugh because they were overdone (yet satisfying) Highlights: - Strong acting. It felt like the actors made the most from the script. - Unique premise. I love the fantasy aspect of traveling forward in time and discovering while new technologies have been formed, the human psyche hasn't. The loveline in this drama was well done for its subtlety, which is fresh in the kdrama world. I haven't watched that many crime dramas yet, so I see there is a lot of potential in korean dramas. Overall can't quite compare to CSI and the like due to plot holes but stronger than American TV shows in the character development and overarching plots. Looking forward to watching more of them!