vcs pac-man for me represents the dividing line between old atari (vcs) and new atari (2600). in the days before pac-man, just getting an arcade port on the vcs was a treat and people were mostly happy. accuracy was pushed aside and programmers instead pushed the unique qualities of the 2600 in ports of defender, asteriods and space invaders. pac-man took the same approach, but after pac-man was released, atari changed its strategy to more closely represent the arcade original.
so if you compare pac-man to early games, the extra primitive graphics and sounds fit in quite well, and the game is well done. if you compare it to later atari games and activision/imagic/m-network/etc games, its not a pretty sight.