Both dramas:
- are set in the realm of deities;
- have an unforgettable love;
- have an heart-wrenching love story;
- secondary characters that made the main leads have misunderstandings;
- heavy fantasy with many creatures from Chinese mythology;
- beautiful scenaries;
- good CGI (Heavy Sweetness, Ask-like Frost one seems better).

Scarlet Heart is set during the reign of Kangxi ( 1661 – 1722) while Rule the World is set at beginning of Qing Dynasty. The male lead is Huang Taiji (the first actual Emperor of Qing Dynasty ) while his father is Nurhaci, is the founder of Qing Dynasty.

Scarlet Heart and Rule the World have a similar plot: a woman who goes back in times and gets entangled with the princes of the reigning dynasty.
So if you like the first drama, you could like also the second.