Really? What difficulty are you playing at? Is there a point in particular you have a problem with?
I'm playing on Normal. I'm towards the end, but the part that I was stuck on for a little over an hour was the flying dreadnoughts. You have to destory 5 airships. The first ship you just fly to the back core and destroy it. The last 4 ships you have to destroy a core in the front that fires lasers and then destroy the core in the back; however, on each successive ship has more enemies and guns which spam lasers at you.
The thing that frustrated me the most was that there are so many enemies that are capable of being locked on that the camera becomes difficult to control, and I had trouble locking on to the front core. I would constantly get to the 4th or 5th ship, and die... There is no checkpoint either.
ZoE2 has a lot more going on in it than the first which makes for some exciting fights, but it also leads to frustration as the more enemies on screen make the camera difficult to control.