Aliens Colonial Marines
60 Achievements
1,250
35-40h
Xbox 360
Entry Prohibited
Kill 10 Xenomorphs that are using vents
20
How to unlock the Entry Prohibited achievement in Aliens Colonial Marines - Definitive Guide
PuritanSoul
TrueAchievements
TrueAchievements
This acheviement should come with natural progression, and I unlocked it before the end of the first mission.
That said, I understand you can make use of the checkpoint system to boost this if you want - this best place I have seen is towards the end of the first level, when you enter the Cargo hangar to let in the drop ship. When you first enter the room, a xeno will pop the grate on the floor in front of you and crawl out - relatively straightforward shotgun kill. I know this one counts as my acheivement unlocked after i blew him away. So if you really want to boost the cheivo, just make the kill, then restart the checkpoint.
That said, I understand you can make use of the checkpoint system to boost this if you want - this best place I have seen is towards the end of the first level, when you enter the Cargo hangar to let in the drop ship. When you first enter the room, a xeno will pop the grate on the floor in front of you and crawl out - relatively straightforward shotgun kill. I know this one counts as my acheivement unlocked after i blew him away. So if you really want to boost the cheivo, just make the kill, then restart the checkpoint.
Grifter, Reborn, DLC, by, littlejay
"Vents" are a very broad definition apparently. Any opening that aliens are exiting from counts toward this achievement. I had this finished before completing mission 1 on recruit. If you're not a good shot, use the grenades and the grenade launcher (pressing 
when using the pulse rifle) as soon as aliens appear in rooms along the floors and walls.
DarkPhantom89, TheRealClayman
This should come naturally during the course of the campaign as you will encounter many Xenomorphs using vents. I personally earned this in the second mission without intending to.
DARTH ROMUL
stratege.ru
stratege.ru
This guide was translated automatically.
Cumulative trophy. You will have many opportunities to get it in 1 mission, just carefully watch the surface of the walls and ceilings in narrow passages and compartments. In any case, you will receive it automatically by the end of the game if you quickly respond to the appearance of strangers.
