Moriarty's henchman Smiley holds up a string of badly-cut counterfeit coins that are in the shape of space invaders from the classic arcade game, even adding a sound effect from it.
When Martha's father is dangling from Moriarty's hideout, there is a moment where he not only visibly strains in a way very similar to how Lupin did in a similar predicament in the earlier film (which Miyazaki also directed), but also the shape of the section of the building that he is hanging from is not wildly dissimilar.