Chinese is the most superior and have more "blocky" characters. Japanese is the more technological of them and have more "cutesy" characters. Korean...they sing pop...I guess....they have "circular" characters.
So, image below is in this order: Korean characters, Japanese characters, and Chinese characters.
I dont know a lot about the languages, only about their appearances.
I think the korean and the japaneses eyes are a bit more open than the of the chinese. And the names are a bit different too. (So far I know)
Exp:
Chinese: Xiaomeng Li
Japanese: Yuri Ishiyama
Korean: Park Jae Sang