Compelling story, great voice acting, and believable locations make this a top-notch adventure game.
Technically, this is not the flashiest game you'll see this year (or last year, for that matter). This is not, however, a FPS, and the graphics are not the biggest concern here. That said, the visual quality of the game is definitely appealing. All of the character models and locations are unique and well executed. The interiors are populated by attractive (or sometimes grotesque) objects and decorations and all of the character models are appealing if not life-like. The animations are fairly fluid, as well. Although the graphics aren't going to blow you away, they are definitely at the top of their game compared to most adventure titles. The sound is great, with an engrossing soundtrack, realistic ambiance, and genuine and accomplished voice-acting. The game suffers from almost no glitches, unless you Alt-Tab out of the program, in which case you might experience problems with water textures.
The real place where this game shines, however, is in the story. Built upon the legacy of Sherlock Holmes, the developers were very clever in basing this particular mystery around the mythos of the writings of H.P. Lovecraft. Without giving away more than the box: This is an occult mystery which sets the master detective and faithful Doctor Watson on the global trail of a cult of fanatics devoted to an ancient and evil god. The story is very well executed and very involving.
Another highlight of the game is its puzzles, as this is the real bread and butter of any adventure game. Fortunately in the case of this title, all of the puzzles fit into the story very well and feel very rational. You won't find yourself searching all of london for a box of matches so that you can find a clue. Everything that you need is fairly accessable and most of the puzzle solving in the game is a matter of investigation and information collection. Once you have completely observed and collected all of the clues, the story will move on. There are times, however, where you will need to make your own deductions. This is handled interestingly as Holmes puts the question to Dr. Watson of what should be concluded and you must type in a simple word or phrase to answer. This keeps you feeling involved in the detective work since most of the time Holmes makes the deductions automatically. The only complaint I might have, actually, is that in a game where we're playing as the mastere detective, I'd like to see a function for making our own deductions more often so that it's less of a scavanger hunt feel to the game. The developer did experiment with this in part, however, and should be given credit for that.
In closing, I would definitely rate this as one of my favorite adventure games. The puzzles themself were much more accessable and made much more sense than many other adventures, and the story was very compelling. The graphics were average for the time, but exceptional for the genre, and the sound qality was exceptional overall. The game suffers from very few technical issues, most of which can be avoided or are superficial. Definitely a must for any fan of the genre, Sherlock Holmes mysteries, or H.P. Lovecraft's writings.