Less than stellar collection.
It's the lack of additional games and the quality of some of the other games included that lowers the score for me.
Pac-Man Vs is sort of fun. You can play up to 4 people wireless, alternating between who plays Pac-Man and who plays the ghosts. Only problem I have with the game is that while Pac-Man can see where he's going, the ghosts have a limited range of vision and I think there should have been an option for both Pac-Man and the ghosts to see the playing field the same way.
At least for me, Mappy and Xevious haven't aged as well as Galaxian and Pac-Man and seem as just filler.
Beyond filler are the games Dig Dug II and Tower of Druaga which I found to be just awful, not in translation to the DS but just in original game play.
Considering all the great titles Namco has, including only three of them in this collection, it's a pretty pathetic collection especially considering the excellent collection Konami did with their collection on the DS.