I'm a big fan of both Sherlock Holmes and the Cthulhu mythos, but this game falls pretty flat. The low production values constantly prevent immersion, as the character animations are jerky, misaligned and off-putting, the environments are somewhat dull and empty, and the voice acting is fairly bad, aside from Holmes and Watson, who are passable. The puzzles vary wildly in difficulty, from simply picking up an object and using it somewhere else to decoding a very difficult cipher, and often you'll require items that are easy to miss because they blend into the background. For the most part they feel like busywork and most often lack the satisfying feel that you get from solving a puzzle in other adventure games. There are also a lot of parts where you can't use an object yet until something else arbitrary happens, despite there being no logical reason, such as a lemon tree that protects you from mosquitos... but you can only pick the lemons AFTER you use it as a weight in another puzzle, leave, then come back later. Watson is portrayed as a bit dimwitted, something I was never fond of, and the plot, while understandable, is a bit convoluted and not very engaging.
This remastered edition adds a third-person perspective, a terrible addition that only slows the game down more and makes the controls more awkward, and I recommend switching to first-person and staying there.
In the game's defense, the parts set in Louisiana manage to generate some atmosphere, the few areas where Holmes encounters the cult manage to be somewhat creepy and disturbing (the trees that seem to sway on their own were a nice detail), there's one surprising twist, and they don't completely botch the source material. But with so many other mystery and Lovecraft games out there now, this one has very little to offer in comparison, and is probably not worth your time.