Loopholes are everywhere. I do not understand the logic behind the "portal". and there are many scenes that you, as the viewer, may have to assume that 'maybe they brought it with them'. also, though I like Xing Fei, there are parts in the series where her expressions do not match the scene, and Xu Kai Cheng's acting is awkward (for me). Also, the chemistry between them is sometimes a little bit too forced to my liking.
What got me through the series is the fast-forward button; without that, I would have dropped this series after the episode where they got back to the 'modern' world.
What I hate the most about the story is the lack of communication between ML and FL. and I really hate the character of An Jingling, like what is wrong with your logic!!! you that is known to have a good mind is lacking logic. Like where is the logic in that!!!