I wandered here from TV Tropes, and after reading this page, I was reminded of BTongue's "The Shandification Of Fallout". Paraphrasing him, films tell the viewer a story. In a good game, the setting IS the story. The story is "Player Character and the Exploration of X." Like you said, "the player as outside the cages, and the puzzles as locked up within." You and Chris Avellone should get together and create something at some point in the rest of your lives.