Hi there -- thanks very much for playing! There are a few variations on the endings, your cell phone provides a clue as to whether or not the doll is in the room. I'll have to look into what could cause you to choke on the salt water prematurely.
There's a secret ending involving what you name the doll, and the other endings are dependent on leaving the door unlocked. Your character has a hidden fear level, and in retrospect it's not obvious enough. A lot of the shortcomings were a combination of lack of time and running out of energy as I'm also working on doing an enhanced version of "House in Hellworld" my first VN.