Not hard at all, but very good! 5 stars!
Very good game.
But what's Discipline?
It gives bonus to fire rate.
This game was pretty fun. My only real complaint (apart from the poorly written dialogue) is the extremely long and tedious grind to level 15 required for medal-hunters such as myself. And of course once you've got all the other medals, the final boss is a joke.
its so cool