No, there are no curves at all - and not paper pieced either. Honestly, I have never done paper piecing!
Let me see if I can explain it. You take your squares of fabric that you start with and stack them all up nice and neat. Then you take a piece of paper or cardboard or something and draw a shape on it. For 5 squares, I believe it would be a 4-sided shape, but not a square. You put that in the middle, then use the ruler and rotary cutter and cut the entire way across the pile of squares following one side, then you put that pile of fabric aside. Then you cut along the next side of the shape, and put that pile aside. You keep going until you just have the middle pile that is the center. Then you take one piece of fabric off of the top of that pile and put it on the bottom. Then you take 2 pieces off of the top of the next pile and put those on the bottom of their pile. Then the same thing with the next pile, only you move 3 to the bottom, and so on. So then if you look at all of the piles together, you still have a stack of 5 squares, but each piece of the square is a different color, and you just sew the squares back together again.
Like I said, it's really hard to explain - but it's super simple to do. The instructions have pictures.
Oh, and I did get the email - it came through for me just fine.