I also played in Normal mode and I think it could have been harder. Some bosses were tricky and I had to speed up their purification a little bit, because they would have done that with me instead. It's not hard if you know what you are doing. Altought, if you don't get familiar with the system fast then you are just screwed. I always enjoyed the Cave of Oblivion. Also I made it through Seraphic Gate, but that one last boss was just kicking my butt (even the usual enemies in the last part of Seraphic Gate). Especially if she uses her special attack. I get like 200.000+ HP damage. Once I was able to take about 400.000 HP of her energy. I wasn't able to do that again. =/