After a very long session of AvP, and dying multiple times, having to do the level over, and over again... I managed to complete the second level of the Marines.
You have no idea how frustrating it is getting to the end of a level, and then having to start all over again, it is not funny, but I pressed myself forward.
One instance I was aiming a perfect shot at the gas canisters next to the Matriarch, and just as I released my grenade, some damned Alien Drone jumped right in front of me, killing us both instantly. Now that...... is incredibly annoying, but still I pressed forward (but was very tempted to go for extreme Nerd-Rage).