“… when it comes down to it, Portal 2’s greatest love is not for its script, its puzzle design, its characters or its mysterious universe; this is a game that loves The User.
Playing Portal 2 made me feel good about myself, and good about the people who designed it. What’s more, I couldn’t shake the sense that the designers felt similarly about me, about the players for whom they designed the game. It’s odd that a videogame should earn special recognition just for respecting its players, but Portal 2 does exactly that.
Portal 2 is simply a game that wants to be played—it desires nothing more than to be opened up and studied, mastered and thoroughly enjoyed. Its puzzles are begging for your brain; they can’t wait for you to say, “Ah-Ha!” before opening a door and plunging into space, tumbling head over heels towards your next brilliant and confounding challenge.”
-Kirk Hamilton on Portal 2
A spoiler free review of Portal 2 and the above quote really nails how Valve feels about their users.