Quoted from mbaumle:

If I'm playing in the arcade, it's all about the extra ball, maximizing play time, and trying to place my initials in a high score slot (there's nothing better than smugly walking away from a game with the high score music playing, and your initials flashing).
At home, it's all about progressing as deeply into the rules as possible. Getting extra balls and specials are nice, but since there's no "risk" in losing out on a buck or two, I just want to complete as many objectives as possible.