I just beat it. I hope more games use that technology, cause that was awesome. The script is hilarious, too.
if you get the PC version, you can switch the maps and shit around and play half-life 2 with the portal gun. look it up on youtube. http://www.primotechnology.com/2007/10/17/half-life-2-portal/ let's you put portal gun in most source powered games..or something like that.