I was very excited before watching this drama since I had never seen a kdrama with such a concept (the timeline), however, in the end, the plot/theme about destiny and political thrill was very basic.

The actors, without a doubt, delivered amazing performances, and as someone who has never been a huge fan of Song Joong Ki, I was very impressed with how effectively he handled both of his roles.

The music wasn't particularly memorable or unusual, but it was better than nothing...(I love the artist though).

Now for the plot. Half of the first part was slow but bearable because it was mostly about getting to know Arthdal, but it picked up a little in the second half before slowing down again. The second part was when the repetition became worse they would talk about the same things over and over again, about the children that would destroy the world, about Tagon, the antagonist, who didn't have thought of his own, his convoluted love life, and the random characters thrown in with little or no context Not to mention the near-impossibility of character growth.

The whole political issue was nothing out of the ordinary. To be honest, I expected politics in this drama, but it was the same old "I'm going to murder you to acquire power" mentality. No one really used their brains, except Tae Al Ha. Speaking of Al Ha, her father, his death caught me off guard; he had been portrayed as wicked throughout the drama, but right before he dies he is this ambitious guy, that wanted to save his tribe. The problem here is they could've invested more into the mindsets of each key character, which would've prevented the constant confusion.

I can't talk about each character but the overall presentation made the timeline of the story too much of a big deal that they didn't realize it was failing.

The cinematography was one of the things that disappointed me the most; they should've spent more time on the cinematographic concept as well. I wanted to witness the supposedly 'magical' situations as stunning sights at times, but that didn't happen. I wasn't going to say this, but even Hotel Del Luna had a lesser budget had stunning cinematography.
Ultimately, Arthdal Chronicles came through with a new concept but the plot still needs more work. I think a lot of people were so fascinated by the concept that they didn't pay attention to the growth of the plot.

Despite all I've said, I'm still waiting for the second season since I feel it has the potential to improve.
It has the potential to be a masterpiece, but it isn't....well, for now :)