Another reason for having this variety of environments is to provide an incentive for the player to keep playing. In a horror game the core experience that you are trying to evoke is terror, which is not very pleasant. This is in stark contrast to most other games where the core gameplay loop is usually enjoyable in its own right. In a horror game, you are always running the risk of the player quitting, because of the game being too successful at doing what you set out to do! If the player knows that there will be something new and exciting ahead if they manage to overcome their current ordeals, then they are much less likely to drop out. The promise of new environments works well for this, as do other things such as captivating narratives or unsolved mysteries. Of course, Amnesia: Rebirth will have these things as well – some of them are hinted at in this trailer!