Like others have said, your game has a great atmosphere and the mounting pressure of getting the key buttons correct adds to the suspense. The three things I would change are:
- I wish the key mashing was slightly more forgiving.
- I couldn't find an obvious restart button which meant I had to close and open the game
- The raw image grey filter wasn't anchored to fit the whole screen so I got some small border around my game. (I was playing on a 1440p monitor)