I solved it, and saw the animation of the piano moving in the background, the piano is stuck on my screen and my mouse cursor completely disappeared after a moment. I can't click off of it like in the other minigames. By guessing where the mouse is, I'm able to click the Menu button in the upper-left and when I get to the main menu screen, the mouse still isn't visible but I can click the Play button again. The mouse is always visible outside the game. If I exit the game and restart it, it brings me back ...

+ 6 Badges + Point Store Items (Backgrounds, Emojis etc.?) Would be a nice Addition to this Game too.

The linked walkthrough in the game is really useful but if you want explanations for the puzzles, have a look at my walkthrough. I'm not sure if links are allowed on this forum but just search for me, Suzie's Great Escapes, on YouTube and you'll find me! https://youtu.be/S7dtGRvWujM ...

In the bonus book at the end that you gain access to if you find all 4 secrets, there is a special code. That code leads you to a URL. Since Igor's site is down, you can use wayback machine at archive.org to access it. This is the one I was able to access: https://web.archive.org/web/20180416235210/http://krutovig.com/through-abandoned-3-the-refuge-secrets/ Igor and his site seem to be missing in action and I really hope that he's doing ok and just busy with other things....

The 4 Secrets Achievement isn't unlocking for me. Touched all of them, it unlocked the blocked section at the end and touched and read the book. Played two games hoping it was just a glitch but no luck.