You didnt finish?? Shame on you! No cake for you then

There were a couple of spots there that took some twitch reflexes, but most obstacles could be overcome with strategy, though at times not always readily apparent.
The new one has cooperative game play. It is supposed to have much more content as well.
I think my best speed run through the original game was like 45 to 50 min or so. Im ashamed to admit how much I have played the original game and the challenge maps associated with it after the completion story. Having gamed since the 80s I had become kinda bored with modern PC games until Portal. Very original concept.