This game is not for your everyday average casual gamer, and I felt that myself. I was really frustrated by the lack of instructions on missions, hard puzzles that required memory and attention, I confess that I used a walkthrough that I found online, and is the only game that gave me a headache throughout my 25 years of videogaming.
But the story is gripping and the symbolism is thoughts provocative , not gonna spoil it, (somehow reminded me of Prey and of Gravity movie) - I haven't played Alien Isolation yet, but it's on my list, I know Jon McKellan is the mind behind that too, also I will play Stories Untold which is created by the same team that did Observation.
So many people that gave a negative review didn't even understand what happened (you can find a better explanation on their wikipedia page - I always do that after I finish a game or a movie).