Alex Bruce gave a pair of talks at GDC 2014 on the development process of Antichamber (trailer)

In the first talk he talked about the journey from Unreal mod to full game, presenting at game festivals, networking, the grueling work of getting the game to market, and the lessons he learned along the way:

Antichamber: An Overnight Success, Seven Years In The Making

In the second talk he went over the iterative design process, and how he tweaked things based on how people interacted with the game (spoilers):

Antichamber: Three Years of Hardcore Iteration