In what this game is bad ? This game is very good and the hard is rather easy (~5-10 mins)
If you don't success that's because you are not really skilled,
But if it's because the game's lagging, it's your computer that is bad
How to "complete the EHUP"
On the chapter's three first level, go to the right side, throw a smoke circle by aiming the thing then run to it ("follow" the smoke)
That's all
I don't understand all these comments about the "crappy energy system" etc... You have enough energy + PvP ticket then Raid (further) to play enough time