TLDR; The game is pretty good :-) and the puzzles are hard but almost universally fair.

You play as Sherlock Holmes as well as a number of supporting characters (including the best 'good nose' of London, the dog Toby) and use your logical and analytical skills to find your way through devilish puzzle contraptions, classic adventure game item combination tasks and actual detective work, with the three about evenly split.

The game starts of very strong and mostly keeps up both pace and stakes throughout the adventure, only the final sections are somewhat of a letdown. And the ending is a bit weird, but that will not ruin the fun in any way for you. Note that this is a purely linear story, one big and quickly escalating case with many moving parts. It is an original one too, not a re-telling of events from some novel or book by Doyle. And overall, it is pretty good with only a few bizarre transitions that are so typical for adventure games. Still, execution is not flawless.

Visually, the game is a treat if you play it on PC where you can actually get a fluid framerate as opposed to the console versions. Controls are a bit stiff but since its not an action game, that does not really detract much from the experience.
One thing you must be comfortable with is the actual SEARCHING involved in this game, you are expected to actually investigate the 3D world in great detail and look at a lot of stuff very closely. The scenes are expertly set up, with each item and set-piece, as well as its state and position, being relevant to the case or at least giving you sense of what happened before (which is, as said, often relevant to find those elements you need to interact with). Do not underestimate this.

Adventure fans craving for a challenge, buy! Others, take care!

One of my favorite stories in the Frogwares Sherlock Holmes series. This is my fourth time playing through this game (as I originally played it on PS3 back in the day), and it feels so natural to play on PC. If you're looking for a Sherlock Holmes game, this is a great option, especially if you don't have a super modern PC with the specs needed for, say, Chapter One.

(For people buying the game nowadays, I will give one warning: the PhysX driver downloaded with this game is outdated and won't work when trying to boot up the game. You will need to go to the PhysX website and download their newest driver.)