Maestro: Music from the Void 

This app is the third installment from the Maestro series developed by ERS Game Studio. The game is filled with dozens of challenging puzzles, plays a fitting background music, provides you with nicely-drawn graphics, and comes with a comprehensive help guide.

You play as a detective whose objective is to investigate the disappearance of two students and their professor from the Music Academy in Vienna. You will interact with various characters who will provide you with hints.

The app offers a help guide that comes in handy to players who are new to this type of game (hidden object), allows you to toggle fullscreen or windowed mode, and lets you adjust the sound volume according to your needs. What's more, you can create multiple player profiles.

The only aspect I don't like about this game is the fact that it requires an app restart in case you wish to change the display mode (fullscreen or windowed).

Briefly, Maestro: Music from the Void is a hidden object game that brings a fascinating storyline and dozens of puzzles. And since it comes with a reasonable cost, I can't find any reasons why you shouldn't try it.