Interesting concept, which can be further improved by having a better atmosphere in the game.
From the start I did not know what to expect. The idea of the office and an imaginary or invisible enemy is truly great, but you need more than that. At some point during the gameplay I felt bored. Maybe the rooms are randomly generated and the gameplay experience is different for everyone, but it was not that good for me.
My personal suggestion would be adding small details to the game, subtle scares, moving objects, maybe even closing doors. The hiding spot was truly wasted for me and I did went through 50 doors and nothing happened.
As I said, the game has a huge potential, it is good and can be improved by adding minor changes. Best of luck with the future developments.