The speech is called “Games as Instruments for Observing Our Universe”, given by Jonathan Blow at Champlain College in Burlington, Vermont in February 2010.
The talk is short — about 20 minutes — followed by about an hour Q&A (in a separate file). Slides in ppt format are included.
The next day, we did a conversational interview at the Firehouse Gallery in Burlington. This started with a short introduction about Braid and my next game, followed by some questions by Chris Thompson, and then questions from the audience. Here’s the audio for that session. (You can right-click and pick Save As… if this opens in your browser in an obnoxious way.)