Whats the worst part of the game?
I hate when you meet collins, its a disaster ,you told him ´´pierce is dead´´(patetic), what a problem for him!!!!.Its my question,if he has got a blue uniform why he is a member of pierce team????

The first level. I HATE tutorial missions.

The worst part of the game was for me around level 8 when the game suddenly turned into a fight against human soldiers with no NPCs around and few Things up to the end. I also have the feeling that the first levels of the game were much more "thing-like" and well designed than the last levels.

There were several moments that qualify as "the worst". Every single time the game came up with some random reason for you to leave your team mates behind between levels. Whether it be an explosion that incinerates them and not you, a vent you have to jump down that they can't seem to get through, or that they'd simply rather stand around with their thumbs up their asses as opposed to following you, it was by far the most annoying thing about the game! Only one NPC was given a legit death within the plot, which was the Doctor fellow who got shot. The rest, well...

In this case, I would say that the scripted burstouts were the worst. I hated it when a NPC just bursted out while I had just -*test*-('")ed him and he was human. This was really annoying as the infection and wondering about the NPCs should have been the heart of the game.

I take back my comment about the first level. One of the last levels in the game (can't remember which one) has you go down a few flight of ramps fighting off things, NPCs, and auto-machine gun turrets, while your only two teammates inexplicably either die or become infected, only to get to the bottom and be bombarded with more bullshirt machine gun turrets. Some people would call it challenge, I just thought of it as plain annoying, especially since you have to start the WHOLE DAMN LEVEL over again if you die, which happens more often than not. Other than that, most of the levels were rather fine playing through IMO. Much moreso than Extermination at least.