Apartment Life in some ways is a retrospective game; the designers are modernizing content from the original Sims that has been long requested by fans. Things such as the heart-shaped vibrating bed and circular staircases are finally back. This also promises to be a “big” expansion, in that now you can finally build huge apartment buildings populated by multiple families. To keep the frame rate from dying, a “fog of war” feature ensures that the only things that you can see are your sims and their habitat; if a neighboring sim from across the hall disappears into his apartment, he disappears from sight and you can’t see inside his apartment.
IGN – The Sims 2 Apartment Life Preview