This definitely was one of the more unique games that I've run into!
The one-dimensional aspect is an interesting design challenge. You've gone with the player being able to combat ghosts using the camera, but since the game is 1D aiming becomes a binary "are you pointing towards the ghost" situation. Judging range wasn't that hard either, since if you miss you have enough time to fire again before the ghosts get to you. Thus the only fail state that can occur is if ghosts appear both in front and behind the player at the same time. The design challenge then becomes how to make the camera mechanic a fun yet fair challenge.
Communicating locks, keys, and other genre staples through sound was a clever solution! Though the voice synthesizer you picked can be difficult to understand at times, especially if you're not a native speaker. (It also managed to spook me when I booted the game up. I had my volume up way too high).
There is potential here for full short game!