it's a demo so i would assume they are holding back some stuff so, yes the game has to have some aspects stay the same other wise the possible outcomes becomes insanely high and they have to get the episodes out with in 6-7 months
so we may have more options when we play like leave the teacher but take the surviving kid ?
still an extra character either way..
notice the teacher wasn't in the preview till the end and we never see his face ...and peopel should know previews / trailers are editted to shuffle order of events around..