An interesting idea involving an alternative dimension inside a hospital. It recalled - Stephen Kings "Langoliers", "Kingdom Hospital" and old twilight zone episodes. Atmospherically strong, the set up was great. There were also some very clever 'time loop' moments which always have that head-melt appeal. The story had plenty of vague references which led me to believe that all the ensuing weirdness of - time slips / ghosts / a weird bat winged demon and a rather silly heavy metal attired ghoul-thing would be explained. And THAT was were Dark Floors severely let me down. Based on my viewing the movie gives NO EXPLANATION as to what is behind the events. Whilst, some ambiguity is always expected/welcome in these kind of films. Dark floors took it to new heights of vagueness. I don't expect things wrapped up in a pretty ribbon, but neither should I be left feeling "Huh? .. is that it? ... Did I dose off? Maybe, I hit chapter skip by mistake?" Dark Floors left me with a deeply unsatisfying suspicion that "It was all a dream" which is a shame because up until the last reel I was very much on board and enjoying the movie.