4/5 stars by Carl Burgess of ScreenCritix!
As the movie plays out, the horrors of the experiments are soon brought to the forefront, with the man gradually losing his mind and his grasp on reality. The movie becomes unnerving and rather disturbing. Grenzfurthner proving that you don’t need jump scares, costumed killers, or buckets of blood to truly terrify your audience; you can achieve it with unsettling imagery and sound spread over the course of an hour and twenty minutes. […] Having seen and reviewed a few films from Johannes Grenzfurthner in the past, like Traceroute and Glossary of Broken Dreams, I was really surprised by Masking Threshold. It wasn’t the path that I thought the Austrian auteur would take, but I came away from watching the film, happy that he did. A little disgusted, a little unnerved, but happy. Grenzfurthner has a way of grabbing my attention with each project he undertakes, and Masking Threshold was no exception.