And it was fucking awesome.
I don't consider the next paragraph to have spoilers, because I'm not going to talk about the plot except to say that there was one, and I liked it.
But I will say this: they made the puzzles a lot better. Where the first one had lots of jumping and timing puzzles, this one is more concentrated on thinking: instead of guns that shoot balls of plasma that you have to guide around, there are lasers that shoot continuous beams. Instead of moving platforms that you have to time jumps on to, there are bridges and levitators that are always there (until you move them yourself with the portal gun). It's a really good change that improves the game immensely, especially for playing on a console.
I don't consider the next paragraph to have spoilers, because I'm not going to talk about the plot except to say that there was one, and I liked it.
But I will say this: they made the puzzles a lot better. Where the first one had lots of jumping and timing puzzles, this one is more concentrated on thinking: instead of guns that shoot balls of plasma that you have to guide around, there are lasers that shoot continuous beams. Instead of moving platforms that you have to time jumps on to, there are bridges and levitators that are always there (until you move them yourself with the portal gun). It's a really good change that improves the game immensely, especially for playing on a console.