Realm of Crawling Chaos wasn't what I expected. It's good, but not what I expected. I was looking for a source book that would allow me to (fairly seemlessly) integrate the Lovecraft Mythos into an existing Labyrinth Lord game and while you can technically do that with Realms of Crawling Chaos, the book is more geared towards starting a Labyrinth Lord campaign that works from the information presented from the get go.
That being said, the information presented is very good, very creepy, and very evocative of the Lovecraft Mythos. The art is especially good, presenting itself as a great hybrid of old-school fantasy art that's been driven insane by the Necronomicon.
My point point of disappointment was the Psionics section. While it does specifically present rules for Psionics, they're limited and not intended for player characters. Now, personally, I don't use psionics to begin with - but I feel a game master should have lots of options to choose from.
All in all, Realms of Crawling Chaos is a fantastic buy, especially for less than $5. The folks at Goblinoid Games know how to do old school gaming and with this book they know how to do it with a large helping of mind-bending creepiness.
[4 of 5 Stars!]