Aliens Colonial Marines - How to earn easy XP [360-PS3-PC]
Here is an easy easy way to earn a lot of experience points in Aliens Colonial Marines.
The best point for the farming of XP points on Aliens Colonial Marines is found in chapter 10, immediately after the rescue which is activated with the destruction of the third AA turret. As soon as you step out into the large open area (you will see an enemy with the flamethrower in front of you) stop and do not go any further. In this area the enemies are reborn indefinitely and you can man them well from a raised position with the possibility of earning infinite XP and also of unlocking many challenges without major problems.
When you run out of ammo, reload the checkpoint and repeat as many times as you want. Here is a video that shows it all