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