The investigation is organized around 13 mandates you need to fulfill, allowing the inquiry to be broken up into discrete pieces. In each mandate, you figure out the answer to a question highly pertinent to the murder. When you complete a mandate, you receive a puzzle piece that puts you one step closer to solving the mystery. In a way, finishing these mandates adds considerable realism to the gameplay, but it is disconcerting that the amount of information you have to collect to solve each one is highly uneven. There are times when you feel as if the requirements of a particular mandate that you have been pursuing for quite a while might never be met.

The types of evidence you collect in addressing these mandates vary. Sometimes you need to find a footprint or a fingerprint or an article of clothing. Other times you have to gain information by questioning suspects, while other facts are found in photographs you take. A progress bar shows how much evidence you have found to complete a mandate. Occasionally you have to find one piece of evidence before another becomes available. What is intriguing about the gathering and interpreting of the evidence is that a lot of the information you collect (particularly later in the game) is misleading, causing you to draw incorrect conclusions. You thus have to be quite adept at sifting through the tons of data you receive and at combining clues.

Oddly, there are few of the classic puzzles (logical or otherwise) that one normally finds in the virtual adventure genre, and this is disappointing for fans of this gaming niche. There are, however, more than a few cases in which you have to hunt for a relatively obscure clue that is extremely hard to find, obtain a keycard to open a door, or locate an object to use in an interaction zone. At one point you have to create fingerprint powder, a task you can complete so easily that it’s hardly a challenge. The absence of any significant type of mind-melting brainteaser within this adventure murder mystery represents a major missed opportunity.

Sinking Island gives you a choice of two different play modes for undertaking the search for the murderer of Walter Jones: “Adventure,” a standard mode in which there are no time constraints and you can proceed at your own pace; and “Race Against Time,” a real-time mode in which you have to make progress quickly or be taken off the case. In this second mode, an onscreen clock keeps track of time, with several game minutes counting for a single actual minute. If you keep on track with your hunt for clues, the time allowed is ample, but missteps can prove fatal. Although the “Race Against Time” mode does add tension and nervous excitement to the gameplay, and might be appropriate for other computer game genres, it is alien to the preferences of most adventure gamers, who generally like to take their time and explore the attractive settings to their hearts’ content.