If I think of the Atari games that have held up, they are mostly ports of games that are actually better in the arcade. Space Invaders is good on the Atari, but the arcade version is better. And then there are other games like Pac Man and Donkey Kong where the arcade version is far far better than the Atari 2600 version. If a person really likes 2600 games, then my guess would be that what they really want is to play the classic arcade games.