Very interesting concept and one of the more innovative entries for sure! I really like the approach and the minimalistic design. The atmosphere the game provides is great and with the sounds it's impressive how quickly you can immerse yourself in a game like this.
I agree with a few of the other comments about the sound effects, I thought they set the atmosphere perfectly and wouldn't want you to change them but having more textual feedback around the screen would make a huge difference. Displaying what is being said and providing textual prompts like 'you found a key!' or 'you open the door...' would keep the aesthetic while also helping players to understand, as at times I felt a bit lost even though I enjoyed the experience.
Considering the time constraints you did really well with this and it's an idea that has some serious potential! Nice work :)