For its time, this is a surprisingly potent and interesting Dr. Moreau adaptation, possibly one of the better ones we've gotten on screen.
it helps that there's enough talent around, including Charles Laughton doing a fantastic job as Moreau, Bela Lugosi giving life to a rather thankless part, and a nice array of actors here and there, as well as definite effort being put into the makeup and effects. As an adaptation, it gets across the source material's point rather well without sticking to it 100%. Parker's conundrum between the panther woman and his girlfriend is a pretty nice one, and the Panther Woman is actually handled well.
Is it perfect? No. It does occasionally show its age in the way it handles characters, especially our hero from the mainland, and it does end rather abruptly, but it's still a striking enough feature, and I'm glad I watched it.