Internet Archive has this online:
Classic-Horror.com says "it would please fans of the Hammer film era." Moria has some good things to say: "And in exactly the spirit it was conceived, Horror Express proves highly entertaining," and "It’s not exactly a subtle film, but then it doesn’t need to be."
My favorite quote:
Dr. Wells: Miss Jones, I shall need your assistance.
Miss Jones [looking over at Wells' young dinner companion]: Yes, well at your age I'm not surprised.
Dr. Wells: With an autopsy!
Miss Jones: Oh, well that's different.