They're way more hardcore than you thought. Great achievement guide by the guys at Rooster Teeth...
[video=youtube;AEUULIs_UWE]http://www.youtube.com/watch?feature=player_embedded&v=AEUULIs_UWE[/video]
[video=youtube;AEUULIs_UWE]http://www.youtube.com/watch?feature=player_embedded&v=AEUULIs_UWE[/video]