The blurb for it goes, What If Lovecraft Wrote Comic Books? - and then proceeds to answer the questions in a 48 page PDF for Mutants & Masterminds. Which is not a game I own or play, but which is owned by a company (Ronin Arts) with the mother-wit to pay Ken Hite to write things for them, so I am already well-disposed towards the RPG.
Adventures Into Darkness is essentially divided up into three parts: a quick pseudo-history of Lovecraft's foray into World War II-era comics; background and game descriptions of the various comic book characters themselves; and suggestions on how to integrate Cthulhu Mythos material into Golden Age comics campaigns. The advice looks good, but I was mostly distracted by the first two sections, which are full of in-joke goodness (at least, for fans of Lovecraft. I presume that true comic book enthusiasts have their own funservice). At ten bucks for a PDF, it's worth it for the chuckles and shout-outs - and the artwork and layout have the right feel for the era. For that matter, so does the tone. Obviously, HPL didn't write comic books in the 1940s. But if he had, this would have been the gaming supplement that would have been written about them sixty years later.
Check it out.