Nice submission!
I think I played it to the end, and I enjoyed it a lot! It's simple but clear: the player has to explore the environment with a torch.
The fact that everything was dark except for a thin slice of light is nothing new, but you executed it perfectly! The light angle was just enough to understand the surrounding walls, while asking you to constantly look around. Also, your light occlusion mechanics worked very smoothly, and the columns were a nice touch - it felt quite like a prison to me. So, kudos for the theme implementation! Even the walking animation and the sound effects were spot-on :)