Tutorial:
1. Select the masks (on the left AND right side) whose intersection results in the shape in the middle
2. Confirm it with the button
3. Try to beat all 4 Levels

Credits:

 mark-senna.itch.io/ - Developer
dezior.itch.io/ - Developer
Benjlo - Designer
HDPhil - Game Designer

Paper Sound:
Sound Effect by LIECIO from Pixabay

Other Sounds from
https://freesound.org
and 
https://opengameart.org/