In Portal’s Test Chamber 04, a floor button opens the exit door. The intended lesson is simple: put a weighted box on the button so the door stays open when you walk away.
A solution that skipped the lesson
Early playtesters stood on the button themselves, fired a blue portal through the open doorway and reached the exit without using the box. They solved the room, but missed the relationship between boxes and buttons.
In Valve’s recorded commentary, writer Chet Faliszek explains that the team added a glass barrier to block the shortcut. These early rooms generally teach one intended solution; later puzzles allow more open-ended approaches.
Test Chamber 04 in the released game, with its floor button, glass barrier and cube dispenser. Screenshot: Valve, via Portal Wiki.
Cover art: @drawbrandondraw, shared by @VideoArtGame and @memorycardfiles.
