Sinking Island places the player in the shoes of Detective Jack Norm, called to a private island to investigate a murder. The investigation mostly consists of clicking on everything in every room of the insane private hotel on this island and asking everyone about everything, listening to their endless monologues. Even the island gets bored of this very quickly and starts sinking, so you have limited time to complete the investigation.
Well, maybe. Let me explain.
There are two modes in which you can play this game: adventure mode, which works somewhat like Gabriel Knight 3 (triggering certain events or taking REALLY long advances the time, and new stuff happens, like dinner, or coffee, or dinner, or your wife calls, or dinner), and timed mode, in which you indeed have limited time to finish up the game.
I didn't try timed mode, but adventure mode certainly tried my patience: it's still time-based, but the timing is such that it assumes you want to listen to everyone drone on about absolutely everything. If you skip stuff, you will have lots and lots and lots of free time to wander around and admire the gorgeous scenery while you wait for the next dinner or phone-call-from-wife event.
This is, as I said, extremely tiring. Another thing that's rather tiring is that Norm asks everyone the same questions using the exact same phrase. This is occasionally amusing when he basically calls a young woman a hot chyk to her father's face, but those failures are too rare to make the game so bad it's good, and instead it's just booooooooooooooooooooooooooooooooring.
The game is also advanced by solving several posed questions like "Who killed X" or "Was Y stolen?" For those, you go into your PDA-like device, which presents you with a list of empty clue fields you need to populate with the things you found -- photos, footprints, fingerprints, items, statements, and documents. So, for example, the "Was Y stolen?" question might require a document, two fingerprints, a photo, and four spoken statements. It is up to you to find the correct ones (thankfully the game will tell you how many you have) and use the Clue-inator to verify the solution, at which point it's spelled out for you again. You also use the PDA to check peoples' fingerprints etc.
Fortunately a person I needed to talk to vanished mysteriously and then the game crashed, so I watched the ending on YouTube. Absolutely everything is laid out in that ending, so ... the developers themselves didn't think anyone would pay attention? I don't know or care.