Portal is a first-person puzzle game. Players must solve physical challenges by opening portals to maneuver objects, and themselves, through the enigmatic Aperture Science Laboratories.
This was nearly wiped from the internet, so I'm uploading it to here. a nice permanent home for it. readme says "These files may be distributed as part of a larger package so long as credit is given." so, all credit goes to Curtis Bratton! ^^ (also, thanks to portalplayer for having one of the remaining copies of it :D )