This is a great show. The first half reminded me of the american TV-show Lois&Clark, for obvious reasons. I loved that show as a kid, Healer's take on this theme was good enough to keep me entertained as an adult. The second male lead was also a bit similar to Lex Luthor early on. The second half is not as good, but it is still head and shoulders above the average Korean action/thriller flick. I always felt that Hallyu cannot compare to american thriller shows like The Americans, or Person of Interest. The action/thriller part of Healer doesn't quite match up to them either, but it's certainly interesting enough. Thanks to some kdrama tropes & the pretty romance this can be considered a different genre though, something the American shows cannot really match either. It's certainly lightyears ahead of Descendants of the Sun, to the point that all the action/thriller scenes in DoTs can be considered a joke in comparison. It's nice that there was no triangle, or other relationship shapes, that was a pleasant surprise. The main actors were all very good, there is some surprisingly good acting from Park Min-young, this is probably her peak as an actress. I loved her in Secretary Kim, but she is MUCH MUCH better here. This is the first time I've seen Ji Chang-wook on screen, but he seems like a very good actor too, he did very well with his fake personality and everything. Obviously there was sizzling chemistry, no surprise there.
To mention some negatives, I really did not like the "tense music track" that was playing all the time, it's a pretty bad earworm too. Also there were some cartoon-ish villains that we could've done without, there were some moments that felt pretty fake too. Also the last episode felt pretty rushed.