Hi,
The game will support both traditional and simplified Chinese and from what I see the currentyl available script is 100% translated into simplified Chinese, whereas traditional roughly 40%.
Thing is, dev hasn't shared all the text that appears in game yet, hence you won't see every text translated, what's more dev hasn't imported the translated script into the game yet, he will do it once he'll be ready to release another update as he does that occasionally.
If you'd like to help the translation team, feel free to join our Discord server and go to specific language thread in Global -> translations channel.
Hope this helps,
Cheers