When robots run amuck in an historical theme park, a shy Chinese boy must battle robotic Australian icons to save the lives of his classmates.

Ned Kelly, of course! Silly me. I like that the kids are Chinese Australians. But, yeah, as FFF says, maybe try to add something to your logline that makes their being Chinese Australian necessary.

As well as make the film more marketable in the very lucrative Chinese market.

FFF. You have nailed it. That is what I am trying to write.