It was a bit long but I enjoyed myself through the entire experience, I feel some of the systems would fall apart if it was less than 10 hours long. Also the game was segmented into unique areas from what I remember so some of those would have to be cut.
I only got to a point shortly after the alien first appears when it would just get into a pattern of walking in circles where I literally could not leave the room I was in without being caught (and it wasn’t like a scripted thing; it was a game over). It happened 3 different times I started from a new game so I kinda gave up on it.
Yeah the beginning is a bit rough because apparently the alien is specifically programmed to not leave you alone in the first level or two that it appears. My initial experience was similar but after the first level it got a lot better.
To me the game either works great and you get a legit scary experience or the alien pops out at the wrong time and you have to briskly walk through the rest of the level or die instantly.