Full list of all 10 Pac-Man 256 achievements worth 1,000 gamerscore. It takes around 4-5 hours to unlock all of the achievements on Xbox One.
Earned a x16 Ghost Multiplier from a Power Pellet in singleplayer
Completed 16 missions
Played a multiplayer game
Fully upgraded a powerup
Ate 64 Fruit pickups in singleplayer
Ate 64 Ghosts while using a Power Pellet in singleplayer
Ate 2048 Pac-Dots in singleplayer
Unlock every powerup
Fully upgrade every powerup
Score a 256 in singleplayer