The cast was amazing and I've always loved Park Shin Hye. She's so talented with her singing, acting and she can pull off badass stunts convincingly!! That being said it took me a while to finish the series even with quite a few characters I loved:

1. FL lead's dad
2. Asia Mart Boss
3. Agent with an obsession to kill FL
4. ML's bodyguard

What worked?
1. Cast / Acting solid from supporting characters to even the young girls that played earlier version of the FL
2. Action packed - stunts were solid (minus some CGI background)
3. interesting characters - could've been more though
4. Set - Beautiful set from the home view of the city to the bunker. High budget

What didn't work for me:
1. Story telling - somehow didn't captivate me. The never ending circles didn't really work
2. Romance - between the leads, am I the only one that felt like they didn't have much romance chemistry? Don't get me wrong ML is a great actor and I loved him in "Stranger" but I didn't feel them 2 worked.

Happy I finished it finally.