Here is the full list of all 25 Pac-Man and the Ghostly Adventures 2 achievements worth 1,000 gamerscore.
Beat the high score on all Pacopolis (Chapter 1) levels.
Beat the high score on all Paclantis (Chapter 2) levels.
Beat the high score on all Space (Chapter 3) levels.
Beat the high score on all Prehistoric Pac-World (Chapter 4) levels.
Beat the high score on all Netherworld (Chapter 5) levels.
End a level with six Health (Hearts).
Complete the Tutorial and all of the Berry Challenges.
Complete any Cyli Hover Board level without losing a life.
Complete any Spiral Cherry Copter level without losing a life.
Chomp every container in any level.
Complete the Lemon Rocket level without losing a life.
Stun 100 enemies with Fire Pac's Special attack.
Freeze 100 enemies with Ice Pac's Special attack.
Stun 100 enemies with Rubber Pac's Special attack.
Attract and chomp 100 enemies using Metal Pac's magnet tongue.
Defeat 200 Blue (Scared) Ghosts.
Defeat 5 Stone Monsters as Granite Ball Pac.
Successfully complete all Betrayus Challenges at least once.
Read the bios for each of Pac's friends between levels.
Get the number of Pac's Lives up to 50.
Grab 200 Pac Pellets in a single level.
Get the Pac Prize score bonus at least once on every level.
Talk to each of Pac's friends between levels at least once.
Win a Gold Medal on every level.
Visit every Arcade Zone in the game.