afefc8c9_of_the_Year___Tales_of_Pandora__Borderlands_2
[Mechanic] Quests: [Borderlands 1] Basic objectives and missions. [Borderlands 2] 
More dynamic missions, ones that affect the overall storyline depending on the outcome (think Fable). Time limits introduced for certain objectives.
Dusty Cartridge – Why BL2 Will Be Game of the Year | Tales of Pandora
Borderlands 2