This is a pretty fun action series, light on sci-fi, heavy on "you need to suspend a LOT of disbelief to enjoy it".
If you approach it like you're watching a Hollywood action flick from the 80s, you'll find it entertaining enough.
The only real problem with this show, and it's a serious one, is the casting of the two leads. They are both easy on the eyes, but they were both terribly miscast for this role. For starters, the girl is a truly terrible actress, and is embarrassing to watch. I'm sure she's fantastic in rom-coms, since she really is beautiful. But this role demanded more, and she was entirely unconvincing--even though I was happy to suspend all criticism and just enjoy it. But boy howdy, is she ever a bad actress. Any situation that requires her to do something other than "be cute" is ruined. With one exception--she does a great job with the fight scenes. But that's maybe five percent of her screen time, and for the rest, you have to watch her acting like someone who has never been in front of a camera before.
But even worse is the male lead. He is a decent actor, but he is *terribly* unfit to be the romantic lead. He and the woman have zero chemistry. No, I take that back. It's not zero. It's _negative_. They are clearly repulsed by one another in real life, and their attempts at romance are so cringey that we finally had to give up on the series after twelve episodes. We only had 4 left, and we were enjoying the story, but the romance was really just as awful and unwatchable as many other reviewers have observed. And honestly it's the guy's fault. He looks much older than her, he acts and dresses cringily young, and he is much smaller than she is (in both height and weight). It's clear that neither of them likes the other, and every time they hug it's like cousin hugs. It was just terrible casting.
The rest of the show is pretty awesome, don't get me wrong. Great pacing, lots of plot twists, pretty decent time-travel sci-fi, and really solid, top-notch acting by the entire rest of the cast. The special effects for the postwar Korean Peninsula are outstanding, and overall the series feels like it had a decently high budget.
If you can put aside your confusion about obvious time-travel plot holes, and you don't mind the male lead pawing at the female lead like a sex offender grooming a 14 year old while she cringes away from him in disgust, then you're in for a fun ride.
