The way you use FMV is very well done. When I first started playing I didn't know what to expect at all. The way you transition from the video to gameplay, then back to video at the end felt satisfying. There is a clear beginning, middle, and end.
The main part of the game spent navigating the dark corridors is an interesting way to illustrate the feeling of anxiety and depression. The bright light that appears temporarily is a nice touch. Sometimes we don't know where we're going, but there are moments of clarity that help guide us. I think you showed that well here.
Excellent work, team!