It's quite an Interesting idea, I like that you played around with a horizontal maze game like this. It reminds me of some old gameboy games where you are basically running around the level going through doors, stairs and elevators. Tried medium difficulty, but unfortunately didn't reach the top floor in time. Stopped at a place where you are going up and down through some stairs only. Speaking of that, this brings to a good point that it would be a nice idea to know what floor you are on, so that it gives the player some urgency and a sense of progress. And something different on each floor would be nice too! Just something to distinguish the floors from each other. Also, some sounds such as office ambience would be nice too.
Anyway, good job in making this game. Keep up the good work!