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