The Internet Archive has it online:
1000 Misspent Hours says that
Corman and screenwriter Leo Gordon somehow managed to turn it into something startlingly serious and mature.and closes the article by saying this:
If it weren’t for the generally shoddy production values and that pitiful, pitiful monster suit, I’m quite certain this would have become one of the most respected horror films of its era.
It is a passably well-made B movie but there is absolutely nothing remarkable to it.
7/14/2009: Classic Sci-Fi Movies has a post.