The browser version is a HTML5/JS horror game with some standard tropes (excape from this haunted house, find batteries, fix the generator) in a PSX-like artstyle, with some standard mechanics (Flashlight, hiding, reading notes). Hitting a ghost with a bat is new but makes no sense ;-). By the way, when the hint regarding the bat was seen I was looking for flying bats as the are typically for Halloween...
I normally would consider it a weak (nonetheless working) game but the dev is 13! For that, it is an achievement to get so far in the first place. Wow! The mechanics were solid enough.
I liked the ambient sound. And, the game has even a controls, settings and credits page! Makes is more professional (but the quit button does not work).
Like Hiisileiri, I could not find the last battery as well. And unfortunately the whole premise of the game - escaping from the haunted house - is forfeited at the start when the game starts with the player outside of the house while the ghost is already visible inside. A thoughtful mind would not enter here (but we aren't thoughtful, we have to rate games! :-) ).
Last remark - from the few notes in the game I did not see the theme shine through. Maybe it is meant that the player is uninvited but this would qualify any adventure or horror game.