Here is the full list of all 100 Mosaique Neko Waifus 3 achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
CLICK A PIECE WITH "SECRET PRESENT" 5 TIMES
CLICK A PIECE WITH "SECRET PRESENT"
VIEW 100 PHOTOS
SOLVE 3 PUZZLES WITH SEDUCED COCO
SOLVE 4 PUZZLES WITH COCO
SOLVE 1 PUZZLE WITH SEDUCED COCO
SOLVE 3 PUZZLES WITH SEDUCED NIKO
SOLVE 4 PUZZLES WITH NIKO
SOLVE 1 PUZZLE WITH SEDUCED NIKO
SOLVE 3 PUZZLES WITH SEDUCED SAYOURI
SOLVE 4 PUZZLES WITH SAYOURI
SOLVE 1 PUZZLE WITH SEDUCED SAYOURI
SOLVE 4 PUZZLES WITH LULI
FIRE "EARTHQUAKE" 10 TIMES
SOLVE 20 PIECES USING "FLIP ALMOST SOLVED"
SOLVE 1 PUZZLE WITH SEDUCED LULI
"LOVE SPARKLE" FIRED 50 TIMES
UNLOCKED "SECRET PRESENT" IN SKI
SOLVE 3 PUZZLES WITH SEDUCED LULI
VIEW 1 PHOTO
VIEW 10 PHOTOS
UNLOCKED "FLIP ALMOST SOLVED" IN SKILL TREE
UNLOCKED "EARTHQUAKE" IN SKILL TREE
UNLOCKED "FLASH BOMB" IN SKILL TREE
"LOVE SPARKLE" FIRED 10 TIMES
ALL GIRLS JUMP OUT OF THEIR CLOTHES
UNLOCKED "LOVE SPARKLE" IN SKILL TREE
COLLECT 30 ITEMS
COLLECT 35 ITEMS
COLLECT 40 ITEMS
COLLECT 37 ITEMS
SOLVE 25 PUZZLES
SOLVE 30 PUZZLES
SOLVE 35 PUZZLES
CLICK THE PUZZLE PIECES 1500 TIMES
SOLVE 1 PUZZLE WITH NIKO
SOLVE 800 BLOCKS
SOLVE 900 BLOCKS
SOLVE 1000 BLOCKS
LEVEL UP TO LEVEL 30
FIRE "CHOCOLATE AIRSTRIKE" 30 TIMES
GAIN 30000 EXPERIENCE
LEVEL UP TO LEVEL 25
SOLVE 700 BLOCKS
SOLVE 20 PUZZLES
CLICK THE PUZZLE PIECES 1000 TIMES
COLLECT 25 ITEMS
SOLVE 600 BLOCKS
SOLVE 1 PUZZLE WITH COCO
LEVELED 20 ABILITIES IN TOTAL
GATHER 7 UNSPENT ABILITY POINTS
LEVEL UP TO LEVEL 20
CLICK THE PUZZLE PIECES 900 TIMES
CLICK THE PUZZLE PIECES 800 TIMES
SOLVE 500 BLOCKS
LEVELED 15 ABILITIES IN TOTAL
CLICK THE PUZZLE PIECES 700 TIMES
GAIN 10000 EXPERIENCE
SOLVE 400 BLOCKS
LEVEL UP TO LEVEL 15
"FLARE" FIRED 15 TIMES
SOLVE 15 PUZZLES
NEW_ACHIEVEMENT_DESC_1_25
CLICK THE PUZZLE PIECES 600 TIMES
UNLOCKED "CHOCOLATE AIRSTRIKE" IN SKILL TREE
SOLVE 300 BLOCKS
SOLVE 10 PUZZLES
SOLVE 1 PUZZLE WITH LULI
CLICK THE PUZZLE PIECES 500 TIMES
NEW_ACHIEVEMENT_DESC_1_24
CLICK THE PUZZLE PIECES 400 TIMES
LEVELED 10 ABILITIES IN TOTAL
SOLVE 200 BLOCKS
LEVEL UP TO LEVEL 10
GAIN 5000 EXPERIENCE
CLICK THE PUZZLE PIECES 300 TIMES
SOLVE 100 BLOCKS
CLICK THE PUZZLE PIECES 200 TIMES
SOLVE 5 PUZZLES
CLICK THE PUZZLE PIECES 100 TIMES
SOLVE 50 BLOCKS
NEW_ACHIEVEMENT_DESC_1_23
LEVELED 5 ABILITIES IN TOTAL
NEW_ACHIEVEMENT_DESC_1_22
LEVEL UP TO LEVEL 5
CLICK THE PUZZLE PIECES 50 TIMES
UNLOCKED "FLARE" IN SKILL TREE
UNLOCKED "PEEK" IN SKILL TREE
NEW_ACHIEVEMENT_DESC_1_21
SOLVE 2 PUZZLES
COLLECT 1 ITEM
COLLECT 2 ITEMS
SOLVE 1 PUZZLE
SOLVE 1 PUZZLE WITH SAYOURI
SOLVE 10 BLOCKS
LEVEL UP TO LEVEL 2
CLICK THE PUZZLE PIECES 10 TIMES
SOLVE 1 BLOCK
CLICK THE PUZZLE PIECES 1 TIME
HELLO THERE!