Two things that really work in this film: 1.) George Zucco as Professor Andoheb, who is the evil high priest of the temple. This is probably the finest performance of his I've ever seen. 2.) Jack Pierce's make-up on the Mummy combined with Tom Tyler who embodies the costume. While he's no Karloff, all of his scenes are good and I like his take on this classic character.
The Mummy's Hand spawned several sequels but none of these films compare to the iconic original, including The Mummy's Hand. As long as you're prepared for more action-adventure and less horror, you'll find this an enjoyable film. It's well made. I just prefer my mummy tales a little darker.
For more info check out the film's entry in IMDB.