This drama was definitely one of the nicer surprises I had this year - within all those other ones I was anticipating alot more, Tunnel actually managed to better its quality from episode to episode. In the beginning I wasn't really interested in this and then people started to compare it to Signal, calling it a cheap copy of it. That made me curious though and I wanted to see it for myself. Now I thank everyone for indirectly making me watch it - because it's nothing like Signal except the time slip theme. At first glance the synopsis doesn't appeal very interesting, especially since there are so many time traveling dramas out there recently. But once you give it some time and don't reject it right away, the story will definitely trigger something inside you. That's at least how I felt about this. I started with low to average expectations and ended up with fulfilling satisfaction. The acting in this started really ordinary. It wasn't bad, but it didn't make me drop my jaw either. It solidly carried the story, as you might say. Choi Jin Hyuk started off quite indifferent, for example. But as episodes went by, he slowly managed to grow on me and make me sympathize with his character alot, especially in the second half. The same goes for Yoon Hyun Min and Lee Yoo Young. Both of them are actors I haven't seen before. I think it's alot more difficult to convince viewers who don't know about a respective cast of a drama and therefore don't crazily fangirl over them. In this case I didn't know about the leads and they were still able to convince me and make me enjoy this drama more than I had hoped for. The more I went into the story, the more I got entangled with its figures - in a good way. Without telling too much, this drama also has an interesting villain who might not be someone new, but surely piques your interest and makes you excited about his character. Objectively speaking, I would actually give Tunnel a rating of 8.5. But due to my surprise and personal entertainment I added 0.5 points to it. Hell, this drama is not free from flaws, I admit that. There were some things in the script and about some behaviors, I got angry about because it was flat-out unrealistic or stupid (excluding the time traveling thing, of course :P). Then again, despite those minor matters, there were other things I happily accepted and which made me overlook the deficits. For example satisfying police work. Hard working officers, most times logical procedures and well done investigations. And the most important thing: No corruption! (a trope I got so tired of). It was also great at connecting and balancing crime and drama, the reason why I got so emotional many, many times while watching. Other things I really loved were the side love stories that captured my emotions and the background music which was used so well and adjusted so perfectly that you even notice the improvement of the scenes through music while watching and listening. There are of course also surprises up its sleeves. Some people might be able to foresee them but I also think that the drama did a good job at revealing certain already known or predicted things to its characters. And it did a good job at confusing (at least) me quite well, too. Or let's say it managed to make me think too much about possible turn of events. And no matter the outcome, that feature added completely to my enjoyment. Cinematography did a really good job many times as well as scene flow and editing/cut. There were moments where I thought "Oh, nice! Well done!". Conclusion of this one: Tunnel is definitely worth the watch if you are able to overlook some minor flaws. There are still many things to enjoy and be excited about. And one thing: This has one of the best final episodes I've seen so far.