The Good
⌲ The leads look great together visually.
⌲ Puff executed the aloof female lead persona very well.
⌲ The cute second lead noona romance
⌲ The workplace banter up until e9.
⌲ The relatively well executed fight scenes
⌲ Effectively speaking the villainous characters don't get any screen time. (I cannot emphasize how great that is compared to the cartoon villain galore that we normally get in dramas)
⌲ There are no love triangles worth mentioning.

The Average:
⌲ The main romance. (there is just unusually little fluff overall)
⌲ The supporting characters at the company felt too average, kind of like they were drawn from a template or something like that.
⌲ The mom is horrible, but on the flip side she has very little screen time, as such causing fewer than average annoyances.
⌲ Recording conversations left and right.
⌲ The weird 13 episode format, did the bad ratings lead to premature cancellation? (then again it's better then dragging the story to 16..)
⌲ There is very little fun banter & main romance after e9, the focus shifts to other things.

The Bad:
⌲ ML keeps hitting on FL, who does not notice for half the drama & then suddenly they are dating.
⌲ The separate bedroom.
⌲ The plot flows strangely. (it's difficult to explain. There are a large number of very emotionally satisfying scenes, but the whole drama feels a bit disjointed.)
⌲ The final episode is fan fiction tier for a variety of reasons, it's really not a well thought out episode plot wise.
⌲ Redemption arc, redemption arc, everyone gets a redemption arc, yay. (no way forgiveness is justified for these people!)
⌲ Friend & exBF ...