Playstation Plus this month gives away to PS3 owners Sherlock Holmes: Crimes & Punishments - also available for pc and abroad. This is a very impressive game, specially if, like me, you're a fan of Holmes.
It's well into IF territory, not just because of its firmly entrenched literary roots, but also because it's pretty much all text: all dialogues, clues and choices are plain text. While you visit and inspect locations through a very faithful victorian London 3D rendition with detailed characters, the real meat of the game happens in Holmes' casebook: all past dialogues, collected clues, map to choose where to go next, etc.
The game combines the methods of Holmes to collect clues - with special interfaces to help us poor mortals - with a neural network-like interface where we combine clues and logical inferences result from them. Essentially, it follows Holmes' art of deduction very closely, but help us a lot by automatically remembering every one and making them readily available.
Then, it's up to us to live up to his standards: we may actually wrong a suspect by choosing a wrong deduction that is still well-grounded on solid evidence and conflict-free logical reasoning (logical conflicts show in red). Not all clues lead anywhere, are just circumstantial evidence. You may rework your deduction graphs and morally weight your opinions on likely motives to get to different outcomes. Not really easy and very well done. The game also lets you undo your conclusion and choose a different one.
The moral aspect and darker undertones of the game are likely influenced by Crime and Punishment from Dostoyevsky, a book Holmes is seen heavily reading in the cabs loading screens. The game was developed by russians.
That aside, the game is the most faithful representation of Holmes in today's media. It consists of six short mistery stories (I solved 3 this weekend) that may or may not be original: the first is pure Conan Doyle - and I've read it in The return of Sherlock Holmes, I think, so I already knew the murderer beforehand - but the others seem original material.
Very nice game overall, it does a wonderful job in characterization, settings and really putting you in the shoes of Sherlock. Some minor issues with framerate (on ps3) and camera control, but this isn't an action game so no points taken.