Incredible story, creative interface, but confusing gameplay.
The story behind this game is excellent in its reflection of the Lovecraft Mythos. It deals with many of the themes Lovecraft used in his stories; madness, cults, powerful creatures from other worlds, mutation and heritage. You'll find yourself being pulled into the mindset of Jack Walters, the protagonist private eye, compelled to discover the truth no matter how horrifying the truth becomes.
The pacing of the game is also a spot where it shines. You feel a growing sense of tension through many parts of the game, which eventually lead up to you either having to fight for your life against deranged cult members and bloodthirsty deep ones, or run for your life while horrors you don't want to imagine, such as a Shoggoth, are closing in behind you.
However, there are game mechanics that are hard to grasp. The combat system can be difficult for those who are too used to having a hovering crosshair in the middle of their screen. However, once you get used to ironsight aiming, this can be quickly overcome. However, when looking at the game's performance rating system, you can get the distinct impression that even being a crack shot will bring down your rating. It seems as though the game wants to force you to be an ineffective weakling, even if you have the stealth and marksmanship to be a serious threat to the followers of Cthulhu, Dagon, Hydra and the deep ones.
Movement is also another problem. While the game does an okay job of giving you the ability to hide, it never does much to give you the ability to get your rear in gear when trouble arises. During most of the game this isn't a problem, but during some of the more hectic chase scenes, it can create a problem when you're trying to sprint down a hallway, but instead feel like you're doing little more then strolling.
In all Call of Cthulhu: Dark Corners of The Earth is a game that I'd highly recommend for an immersive story and an interesting and revolutionary interface. Just be prepared to get used to a slightly different combat mechanic...and to not be rewarded for it when you get the hang of it.