Eldritch Skies is quite a fascinating product. It takes the Cthulhu mythos and translates into a sci-fi setting with a logical alternate history of the 20th century. It presents a space game where there is both wonder and terror to be encountered among the stars.
Shortly before purchasing this I was thinking of having a homebrew setting with aliens that were both much more powerful than humanity (rare in my experience) as well as less advanced (quite common). There is a reason for finding other planets with human populations built into the setting as well as interpretations of the Mi-Go, Deep Ones and Ghouls that work well and will keep adventurers on their toes.
If you like sci-fi, cosmic horror and/or Sorcerors and Starships this product is worth your while.