Sherlock Holmes: Crimes and Punishments is, in many ways, a typical detective game. You look for clues, you interrogate witnesses, investigate suspects, and ultimately decide whodunnit. One feature separates it from much of the mystery pack, however: You can get things wrong. The game will let you make incorrect deductions, draw wrong conclusions and even send the wrong person to prison. The ability to fail is probably the game's best feature, and it's one I wish more detective games would embrace.
It's easy to see why mystery games would be reluctant to let the player completely blow a case. For starters, there isn't much replay value in that type of gameplay, and slogging through a case all over again, hearing the same testimony or performing the same experiments, would lack a certain vivacity. People also process information differently, so what might be a stonkingly obvious connection to one person would be utterly baffling to the next; add differences in cultural references or knowledge into the mix, and the problems inherent in crafting a tightly-constructed detective narrative become obvious. Plus, people just plain don't like feeling dumb, and getting a big fat "WRONG, BUCKO!" after noodling your way through a case would understandably be off-putting for some players. It should be there anyway, though, because otherwise there's no real incentive to put your brain through its paces.