The horror part of it was done almost perfectly, although a bit short. I got drawn into it almost right away, which usually doesn't happen. The person talking to you right at the start was what got me into it so quickly. The mirror is an AMAZING gameplay mechanic, and i think you should screw around with the mirror mechanics and do some really messed up stuff with it.
You have the beginnings of a really, really, good game here if you do decide to expand on it. Adding more passengers and conversations would make the game really work, and maybe even start on your last break instead of directly on the bus. Adding world atmosphere can ONLY add to the experience. 10/10 for what was played.