hello. i am helping my fiancee mop up a few achievements for L4D.
3 more campaigns on expert
Back 2 Help - leave saferoom to save incapped teammate
Slippery Pull - pull bile covered survivor(crash course)
Chaos Generator - all 3 generators started simultaneously(the sacrifice)
choas generator and slippery pull only take a few minutes to do, back 2 help requires a bit of set up (completing a chapter) and the 3 campaigns will take the form of using the easy/expert glitch (if still available) and then using jesus spots or effective spots on final stages. the 3 she needs to complete are death toll, dead air and blood harvest.
her GT is Hez2
i myself also need slippery pull and chaos generator, however i rarely buy LiveGold so i will post again for myself when i next am going to be online.
It's just a game.