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