Sigma was quite tough. Sigma 2 was manageable, compared to Xbox 360's Ninja Gaiden 2, which was sadistic. That was the only game where I had to switch to a difficulty below Normal. Ninja Gaiden 3 was a cake-walk, but Razor's Edge was again quite difficult (at least the demo was). If you don't learn to parry and dodge properly in this game, you're going to die and DIE. The camera is awful at times, so you'll have to deal with it. The best part I love about this series is that, in a battle, no enemy would remain idle, whilst the other is attacking. They would all participate in screwing you to oblivion.