If Mr. Sardonicus had been an episode of Boris Karloff's Thriller TV Series, it would have been O.K. Unfortunately, Mr. Sardonicus feels like a half hour thriller that is stretched to an excruciating 89 minutes. I kept waiting for something interesting to happen, but most of it is actually quite boring.
The biggest problem with Mr. Sardonicus is its premise. A man digs up his deceased father to retrieve a winning lottery ticket. However, the sight of his mummified Dad causes Sardonicus' face to freeze in a maniacal grimace. Stupid! Furthermore, the actor who plays Sardonicus has to wear a mask for most of the film that covers his entire face. Unlike the Guy Fawkes' mask in V For Vendetta  which stole the show, this one is simply annoying. There is no witty dialogue and snappy one liners to keep things interesting. Just a lot of boring soliloquies….and whining. Furthermore, when his face is finally revealed the make-up work is laughable instead of being frightening.
I'm normally a big William Castle fan. [He directed and produced Mr. Sardonicus.] But this one felt like some of his weakest work. He makes several guest appearances in the film as the host and practical jokester. But this time out he didn't win me over.
I know some people like this film, but it just didn't do anything for me. If you want to see William Castle at his best, try Straight Jacket (1964) or House on Haunted Hill (1959).
For more info check out the film's entry in IMDB.