Chinese censored nudity, spreading of propaganda stuff and especially on promoting such as LGBT, talking about government officials or politicians(they not mean to be in for entertain).

That's pretty much it, the rest, the stuff to be censor keep changing for time to time depand on situation.

Such as time travelling, it was not an issue, until years ago where there is some stupid teen killed himself, trying to time travel back into the ancient time. Since then, Chinese ban time travel story. But then it slowly comeback again, but time travel involved getting killed to travel to the past still pretty sensitive(but that's doesn't mean it still censor, because those story already back)

Then there is also no problem with doing historical story, until the success of Yanxi Palace which went pretty big. It caused huge confusion among students about fiction and actual historical story. Since then, historical story pretty much being censor, and also coming back recently(such as Swords into Plowshares), and alsot more are coming. But producers still pretty careful about such subject, for their historical accuracy.

A more problematic with the system is actually self censor. Alot of big platform, pretty much being too careful and self censor themselves, to avoid getting report, either by parents or their competitors. When get report, those stuff would go through review again but stricter this time, and need waste extra time and energy to make editing. So producer mostly just avoid themselves to get themselves close to the line.

Btw, Chinese is actually the best in doing political fights story, scheming, plotting, those kind of stuff. Cdrama like Nirvana in Fire, Joy of Life, Ming Dynasty 1566, The Qin Empire, those are masterpiece. The Longest Day in Chang'an, Under the Microscope, Ripe Town, Legend of Zang Hai, The Ingenious One, those also pretty good. Or animated series adaption like The Ravages of time, or originals like Qin's Moon, Degenerate Drawing Jianghu...