Of all the heroes and superheros of the thirties and forties, the shadow is the most intriguing. In his (Orson Welles-created) radio incarnation, he had a strange superpower. He could be invisible and apparently enter and leave any room effortlessly. On the radio, this was a great effect because of course we listeners couldn't see anything at all. So when one of the characters couldn't see another, it was a sort of narrative fold that drew us in.
Another device was a sort of demonic laugh, a sort of devilish celebration of justice.
How to transport that to cinema? The 1994 version was something of a miracle, one of the best designed movies ever. In that interpretation, the girl was decorous, the bad guy evil and the shadow genuinely invisible as well as having other superpowers.
This one is horrible in all ways except for the effort put into the comedy. The mystery isn't, though it has an interesting device, more improbable than most.
Ted's Evaluation -- 1 of 3: You can find something better to do with this part of your life.