On YouTube i watched a few korean channels review this drama and they said that the FL was annoying at the beginning because she refused to acknowledge the parallel world. However, i found that when watching the drama, the majority of the Korean reviews were very unfair because the acting for me was on point. She was't hateful but she acted appropriately to the possibility of another world, aka not being stupid and bi**hy but not falling for the idea at first glance either. Also, they complained about the romance and how it wasn't enough or it jumped to fast when it got to ep 8 or 9 but i think that it was just enough. It's not sickening with love but you can see how she changes and develops feelings for him through how she looks and talks and acts around him once she experiences his world. You don't need to make it stupidly obvious that she slowly falls for him and that's why i think that this drama is actually better than what people initially said.

also i just want to add that the product placement. for me, wasn't too noticeable, well if i didnt watch the videos on youtube i probably wouldn't have even noticed, especially because im not looking for it, if that makes sense.