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