Z Chamber 12 Developer Commentary

Developer commentary may include spoilers; I recommend you finish PortalZ before reading further.


Panels rise out of the floor to form stairs.
As I have said before, I really liked the concept of Portal test chambers being made out of movable panels, and I really disliked waiting for lifts.  Having the floor turn into staircases addressed both of those.


A hall has a sideways gravity field with a button that used to block it raised up to the ceiling.
Originally, this chamber had a much different layout, with a sideways button granting you access to a sideways fling over goo on the other side of the chamber.  That had the issue of making you replay the entire chamber from the start if you accidentally dropped the cube into the goo during that final fling.  This redesigned version makes raising the sideways button sort of a checkpoint, and also lets you reuse an element for multiple parts of the test.  I am incredibly happy with it.