Storyline is good. And the concept they think of is unique. But the problem is that they should have done their homework about time travelling.
SPOILER ALERT!!!!
In the last two or three episodes when the king was travelling through time, he came across the Einstein-Rosen Bridge (which means he can travel through time). But that doesn't mean that the persons he met would have new memories as well. That was past and it should have been happened despite of how many times he would've met them, because that happened in the past and nothing can change that. And if ID Card of Lieutenant was left behind when he saved himself from Traitor, he shot the other prince who should have been limping from the start. I say that concept was good but they didn't do their homework on how time travelling works. If you want to see a time travelling based series I would recommend DARK. It is one of the best series i think there is based on time travelling.
If you have any comments about the theory i stated or if I am wrong please do tell me. "Wrong information is worse than no information"
Thank You