None. Wang is never clothed but he is an alien so no genitalia is ever visible. In short, you never see Wang's wang.

Some mild punches are thrown.

Light swear words are bounced around. No strong F words are used though.

Wang never smokes.

There's some mild threat and the film ends on a dark note, but overall this is a film the whole family can enjoy. It was awarded a 15 certification in the UK but I'd give it a 12A.