I'm a big Lovecraft fan. I also like a lot of the Cthulhu Mythos writings by other authors over the years. This comic goes in my "like" list. It also goes in my hold box. Here's why:
First off, the art. A good Mythos tale is about atmosphere. Cthulhu stories aren't always scary, as such, but they should always be eldritch and creepy. Jean Dzialowski's art conveys the proper atmosphere. There were a couple of frames where it was difficult to figure out what was going on but nothing that ruined the story.
Dzialowski switches styles a couple of times to show that the action has literally moved into a different realm. The majority of the book has a painterly, stylized look to it which is enhanced by the dark, narrow palette. The art in the Dreamlands sequence is more traditionally comicky and reminds me of Watchmen-era Dave Gibbons.
One of the advantages of writing a Cthulhu story is that there are libraries full evocative, creepy lines from earlier stories in the Mythos. Michael Alan Nelson uses these previous writings to great effect. The story features Abdul Alhazred, the Mad Arab who wrote the Necronomicon. When your main character is the batshit-craziest dude who ever lived you've gotta try hard not to get a good story out of him.
Some knowledge of the Cthulhu Mythos is useful for full enjoyment of this sequential-art product but not essential. Nelson does a good job of filling in the blank spots and Dzialowski draws the hell out of it.
In a time where Cthulhu is the punchline of jokes made by people who have never actually read Lovecraft, it's nice to see someone bringing the creepy back to it.