Full list of all 19 KenKen achievements worth 200 gamerscore.
Beat single puzzle of any grid size on Hard.
Beat single puzzle of any grid size on Expert.
Beat single puzzle of any grid size on Unsigned.
Beat single puzzle of grid size 7x7 on any difficulty.
Beat single puzzle of grid size 8x8 on any difficulty.
Beat a single Challenge Puzzle.
Beat all 3x3 puzzles on all skill modes.
Beat all 9x9 puzzles on all skill modes.
Beat all 8x8 puzzles on all skill modes.
Beat all 7x7 puzzles on all skill modes.
Beat all 6x6 puzzles on all skill modes.
Beat all 4x4 puzzles on all skill modes.
Beat all 5x5 puzzles on all skill modes.
Beat all 9x9 Expert Puzzles
Beat all 9x9 Unsigned Puzzles
Beat every puzzle available in the game (Except for Challenge Puzzles).
Earn all other achievements in the game.
Use the calculator until you overflow it to display "Infinity".