Unfortunately could not live up to the trajectory of the first few episodes, the writer hit the ground running but clearly could not maintain stamina.

It's frustrating because it did start out well, the child actors were good and the flashbacks invigorating but beyond that it fell flat: the love story between the adult Namu and Nakwon was very one note, beyond staring in each others' eyes for endless wasted minutes and a sickeningly repetitive dialogue of "are you okay?/"yes, are you?" there was nothing to believe in. I wouldn't put this down to the actors, I'd say they were more limited by the writing which is frustrating because these are two extremely complicated characters, who've both been through hell and back, battling odds unfavourably against each other and are supposed to be held on for their love for each other alone, all of which is barely conveyed despite the fact it's what holds the whole drama together. After years of being kept apart and a bond formed by an incredibly traumatic experience, once they finally get together you almost wish they'd never found each other it's THAT annoying to watch. The child actors were great I loved their scenes but the later ones were so boring and never added anything new.

It was supposed to be a psychological thriller I think rather than a crime drama which is what it came across as, but there wasn't enough psychology in the lead villain. Heejae is supposed to be this terrifying, cold blooded killer but his relationship with Namu for me kind of destroyed that, he's randomly fixated on Namu as his prodigy which is not supported in the flashback scenes and randomly introduced like five eps in. Additionally, as a viewer you're supposed to believe in this 'dark/evil' side of Namu, to suggest at an ending in which he lives up to his father's expectations of him which to me was absolutely ridiculous. Also, the fact that Namu hit Heejae 'that fateful night' seems like it's supposed to be this huge shocking revelation that changes the tragectory of the drama was ridiculous, like it was apparently so shocking it literally needed to be covered up by the police and then massively changed public opinion once it got out and also was seemingly evidence for why he was destined to follow his father's footsteps....idk should've been scrapped added nothing to the storyline.

Other characters:
Hyeonmu and Okhui were honestly the best written characters I thought, there was a depth and redemption to their actions that was unseen in everyone else, both characters pay the price for their sins and you understand their motives and intentions and love them at the end. Especially Hyeonmu his character was the depth that everyone else in the show needed to be at. Loved both of the actors' acting, and Okhui was for me, the stand out character of the show.
As for the other villains, Jihong was okay, a bit annoying but relevant at least. Jeon Yura was randomly shoved in with no explanation or development, besides from a surface scratch in her confrontation with Nakwon at the end I really didn't understand why she was included.
Mostly the characters just weren't properly developed... Nakwon literally the female lead is never really given a chance to talk through her trauma and vocalise literally anything besides a profession of love to Namu every two seconds.

Also the plot was just so irritating sometimes, like the lack of security throughout actually enraged me, someone was kidnapped and nearly murdered every episode and no one thought to give them a couple guards maybe???? Or put them in a safe house ridiculous.....

Overall, I really liked the cast and I don't really fault the acting I just think it was shocking writing that felt very rushed, for a drama with this much tragedy I never felt moved or really much attachment to any of the characters, I've seen worse and it was definitely enjoyable for the first half but won't be rewatching.