Monday, October 15, 2007
Proving a bit of a toughie, but if your stuck, it dosen't get much better than the following most excellent Video Walkthrough site, with videos on both normal and bonus maps, including least steps, least portals and least time guides including footage on how unlock the 300ft long jump and terminal velocity achievements. Ace!!!
Portal Video Walkthroughs
Orange box achievements list from Gamefaq
Clickable inkies portal walkthrough xbox 360 video walkthrough orange box