Summary: Pac-Man & Galaga Dimensions is a compilation of six games including:

Pac-Man
Galaga
Pac-Man: Championship Edition
Galaga Legions

As well as two new games:

Pac-Man Tilt is a side-scrolling platformer similar to And Yet It Moves in which the player controls Pac-Man, who has the ability to curl up into a ball and bounce from pinball-inspired launchers to eat pellets and ghosts (assuming he has collected a power pellet), and also rotates the Nintendo 3DS in order to shift the direction of gravity.

Galaga 3D Impact is an on-rails shooter in first-person which the player pilots a space ship, aiming with the gyroscopic sensor on the Nintendo 3DS to shoot at various aliens. The ship is destroyed when the shield gauge is drained.