I just beat portal tonight, and it was HILARIOUS. The ending boss was really trying to put you down. And although the difficulty curve in the game rose very rapidly, it was still fun, and I found that I didn't get stuck in any area for more than a few minutes, keeping me from getting bored. The point in the game that really stood out to me though was the end credits and the song that was played during them. This game produced great quality humour right till the end, and I must say that it was one of the best ending credit songs that I have ever heard in a video game.
And just remember, keep on trying till you run out of cake.
-RJ Out