Why is a game about being a delivery boy so good? Is it the infrastructure building mechanic? Is it the batshit insane storyline? Is it the fact that every mountain is climbable? Is it the reserved use of combat and massive punishments for killing people?
Who knows, all I can say is I haven't had this much fun with a game in ages.
My buddy is a truck driver who comes home from hauls in order to play euro truck simulator with his custom wheel setup. Something about the familiarity and the ability to fail without consequence.