Summary: Compared to Portal 2, this game is extremely short, easy (to figure out, but tedious to complete some levels) and just plain sort of boring. I found the voice of the computer in this first game to be very annoying. Portal 2, however, is awesome.
Summary: If you've already played this game in "The Orange Box", don't buy this game. It's the same game other than 14 easy challenge rooms. If you never bought "The Orange Box" and wondered about "Portal"... then buy "The Orange Box". You'll get 4 other amazing games for an extra $30.