This drama should have a long story if they make it solid. It's 20 episodes with 1 hour-long per episode. That should be more than enough to extend the plot.

Unfortunately, they put too much romance scenes and waste the time on it. I hate it when it's actually not necessary but they keep putting it. But, it's not that bad since the "overloaded" romance scenes suit the drama well --> Because of 'love' and wanna monopolize it, they dare to fight with their brothers and spilling the blood for a throne.

It's history-based drama and worth to watch to help you understand a little bit of history of Korea in the Goryeo era.