This page in our guide to Layers of Fear 2 contains the solution to the fruit puzzle which appears in act 4. The puzzle isn't too complicated. You have to find six fruits - this will unlock previously unavailable passages.
The fruit puzzle is solved in the rooms with a lot of red. You need to get to the place where the passage will be blocked by a metal gate (see the picture).
Return to the recently visited room - in the meantime, it will change its "decor". You need to find 6 interactive fruits. We have listed them below. You can get them in any order. You need to interact with each fruit - that fruit will disappear. This will also cause blood to appear nearby. Every time you do that, you will hear a baby's voice.
The first fruit.
The second fruit.
The third fruit.
The fourth fruit.
The fifth fruit. It is hidden in a drawer that you must first pull out.
The sixth fruit.
As a result, the gate has been "knocked down". You can move on.