Well, they don't make them like this anymore. Mostly an homage to screwball comedies... Except it never gets as wacky as you would hope. I noticed Bette Davis disappeared from the movie after a point and apparently she became deathly ill and died 8 months after the movie came out. Eep.
The MVP of the movie is Colleen Camp! I know her mainly as Yvette from "Clue", but she shows she has comedic chops. I think she fully understood the tone of this film; it's a pity the script and directing lets her down.
Sadly, Larry Cohen in a scramble to rewrite the film as they were filming totally lost his mind and started losing track of all the characters and subplots. Had things been weaved together badly the film would've been much stronger for it. As it stands, it is a very messy movie - with a laughably terrible special effects driven finale.
So we have a comedy that is light on laughs... Incoherent on story... But Colleen Camp showing a career that might have been had she not married the head of Paramount. And Bette Davis's last hurrah in an Ed Wood-ian quality final role. Verdict: Worth watching on cable.