Bin Bin

Andy along with buddies Pin-pin and Pancho ventures to Greece to find his long lost friend Shen. They soon discover Shen is being tailed both by the KGB and by Interpol after discovering some rare gems in an archaeological dig. After a unkindly series of events, Andy winds up back in Hong Kong with the stones, which, it turns out, is not gems but rather an alien life form. Meanwhile Karov, an evil magician, is hell bent on getting his hands on the gem/alien no matter what. (imdb)

Two inexplicably identical boys--one a spoiled but unwanted heir, the other a spunky working-class tyke--cause trouble when they decide to exchange places. (hkcinemagic.com)