Criminal Case casts players in the role of a new member of the police force who is tasked with solving a variety of brutal crimes. The first case acts as a tutorial, with the player being introduced to the various components of gameplay one by one, and then subsequent cases become increasingly lengthy and complex as the player progresses.

Criminal Case is split into several parts, each of which advance the plot of each case. Hidden object scenes are handled fairly traditionally — players are presented with a list of objects to find, some of which are key clues for the case, and must find them as quickly as possible to score maximum points. Upon completing a scene, the final score (plus time bonus and additional bonuses for any "hints" remaining) contributes to a cumulative star rating for the stage.