User blog comment:Arbington/New ME4 Teaser Pics, Possible Upcoming Reveal/@comment-1679409-20131114091848/@comment-77.107.190.116-20131115054501

Actually no - ME1 was demoed in 2005 and 2006 at E3 and another game show, with very different builds to what was eventually released. The trailers are on the bonus disc for the ME1 Collector's Edition, and are probably on youtube somewhere.

-Garhdo