Secrets are everywhere in Facade.
It is possible to exit the apartment through the window and explore. although Trip may get angry at the player and attempt to eject him/her. However, due to the large space, one can use the CTRL key to gain a slight speed boost and escape from him indefinitely.
Another secret is that if you say you need to use the toilet, Trip and Grace will be offended. However, this could be due to "toilet" being classified as an offensive word in the programming, much like "melon".