If I'm not mistaken, the trailers focus on co-op, as noted at least once before, because Valve wants to keep the singleplayer campaign a surprise for the most part. It's not because the game focuses exclusively on co-op. Also, the length won't be a problem because we have so many more toys to play with. And the game doesn't need to be simple, so long as it introduces everything as well as the first Portal did. Which I'm quite certain it will.
So yeah. I have absolutely no concerns, and fully expect Portal 2 to be about as good as the first (which, though I love Half-Life 2, is my favorite of Valve's games).
So yeah. I have absolutely no concerns, and fully expect Portal 2 to be about as good as the first (which, though I love Half-Life 2, is my favorite of Valve's games).