Some classic games are so revered that you can't touch them with a 35ft bargepole without having a legion of defensive fans on your back. The truth is, though, that some games just don't age very well. Where some cheeses age gracefully into a stinky delicacy, others just go mouldy.
Pac-Man falls into an odd middle ground. It has aged, sure, but it seems to have stopped ageing, at least for now - like a middle-aged bank manager who has suddenly come upon a 2L bottle of the water of eternal life, thanks to one of those scratch cards that fall out of magazines as soon as you pick them up.