If you've finished the main game and want some more, this DLC is for you. It consists of three more cases that happened in Lemuria. Puzzle difficulty is definitely higher than in the base game. But don't worry, everything still makes sense after you solve the case.
The Case of the Golden Idol is a great game that goes beyond usual game genres. You are presented with a dozen of murder cases, all playing role in the overarching plot. Your job is to indetify who is who, the sequence of events and the motive of the murderer. You prove that you know the answers by filling the blanks in the script with words that you learn thoughout your investigation. It is almost impossible to guess the answers - you best bet is to use deductions and eliminate wrong answers. The difficulty goes up slowly as you gain experience and gather knowledge of the game world - you'll definitely will be prepared for the last case.