Sherlock is a computerized version of logic puzzles, where you're presented with a series of clues that help you to determine the exact locations of all of the images on the playing board. The puzzles are all 4x4, 5x5 or 6x6. Each row of the playing board contains images of the same type (faces, houses, numbers, fruit, street signs, letters, etc). The game scrambles the locations of the items in each row (without showing you their locations) and then presents to you a set of graphical clues that describe the positional relationships of different images. You use the clues to deduce where things can't be (and where they HAVE to be) until you know where all of the images are located.
Sherlock Free contains 10 puzzles in each size for 30 puzzles total. The puzzles in the Free, Pro, Ultra, and Zen versions of the game are all unique, the four versions of the game share NO common puzzles.