Not as hard as Mega Man ZX, and more of the same.
Normal mode isn't as hard as it's cracked up to be, but it is difficult. Here's the clincher; this game was meant and directed towards HARDCORE gamers; I truly do not recommend this game to anyone under the age of 15. This game is "Nintendo hard."
I myself loved this game due to it's balance of difficulty and the many different aspects of gameplay, but I give it a 3 rating because of the fact that not ALL gamers are HARDCORE gamers. I could have been biased and put a 5 because I myself loved it to death, but I gave it a 3 because it's not geared to the majority of gamers out there.