It is rare that I get past 30% on most games...either because its too hard, too big or not interesting or compelling enough to make me continue on. GTA - with all of the online components associated, and some of them are damn near if not outright impossible to accomplish unless you caught it early on (like taking down a Rockstar developer in an online match- I never even met one in my countless hours in the 360 iteration of GTA V). AC and AC2 were just the right size, temperament and intrigue that I felt like going the extra distance (and it was a lot of extra). AC2 same thing. Then I decided to have a go at other types of games like COD and found that the huge online component was prohibitive as well. I'm not a completionist by nature, I just like getting the most out of what I like the most in a game. Usually, that's enough.