In the weirdest of ways, I appreciated the ending a lot more than I thought I would, especially since it was unexpected, but as it unfolded, it made total sense. That only in Han Tae Sul's death would everything be resolved, especially for the future. I admired Han Tae Sul for sacrificing himself in the present for a better future, not just for himself but for all those he cared about, and especially for Kang Seo Hae.
The storyline that didn't work for me at all was Sigma. Things started going haywire from the moment he was introduced. Everything about him was totally insipid; even his manipulation or attempts at manipulation, should I say of the Bureau, Seung-bok, Sun, Han Tae Sul, and everyone and everything in between didn't feel as well-grounded as it should've been for a villain of his magnitude. I mean, he is the guy who brings about the end of the world, yet I couldn't take him seriously.
The other biggest failures aside from Sigma for me were Seo-jin and Seung-bok, as prominent as they were at the beginning of the drama as non-existent towards the end; I almost forgot about their extent when they reappeared, I just wasn't interested nor did I care. As a matter of fact, I wasn't even sure what roles they continued to play even at the end when Seung-bok threatens Tae Sul and Seo Hae rather than menacing it felt contrived and his reasoning, the age-old jealousy felt so uninteresting. The villains in this drama did, however, have one thing in common the intensely personal feeling of inadequacy and hate towards Han Tae Sul for being their total opposite.
As I said, I didn't expect a glamorous ending, but I was pleasantly surprised, not that it was glamorous, but it was indeed interesting. I give it to the writer and director. I liked the last 10 minutes of the finale and wished the show had spent more time reflecting on that rather than on Sigma and his self-pitying, hate, narcissism, jealousy, egotism, obsession, and doubt. I doubted we would get a meaningful ending, but we did -- once we get to self-interpret an ending of our liking. In the end, this was nothing more than a love story.
I enjoyed the first half of this drama. Still, towards the second half, I started getting this feeling that Sisyphus failed me somehow, but then I probably failed it too for not fully grasping its storytelling. I do, however, fully appreciate the acting, especially Jo Seung Woo as Han Tae Sul, Park Shin Hye as Kang Seo Hae, and Sung Dong-II as CEO Park and Sung Dong-II in particular. He was piercing in the role of a broker torn by his past self's emotional indulgences and his present self waiting, pinning to save those who matter to him most yet at the same time failing to recognize they were with him all along. Watch Episodes 15 & 16 here.