Here is the full list of all 69 DEEP SPACE WAIFU: NEKOMIMI achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
COMPLETE ONE HAND JENNY
COMPLETE ONE HAND DIGINEKO
PLAY WITH JOE
FIND THE ULTIMATE RIVAL
DEFEAT SENIOR PICKLES
100% DIGINEKO
DEFEAT DEADNIP
100% JENNY RAZORHEELS
COMPLETE ONE HAND HOMELESS CATS
DEFEAT THE CUTIE GANG
100% HOMELESS CATS
COMPLETE ONE HAND LADY
GET THE FURBALL SPECIAL
DEFEAT UPGRADED CATRON
GET THE CATNIP SPECIAL
100% NORMAL LADY WHITESTROKE
COMPLETE ONE HAND MARY
DEFEAT THE FURBALL
100% MARY KATTY
COMPLETE ONE HAND TIFFANY
REACH STAR LEVEL 30
UNLOCK THE DIGINEKO
DEFEAT THE CATRON BOSS
100% TIFFANY RANCHO
COMPLETE ONE HAND MODE TABATHA
UNLOCK JENNY RAZORHEELS
DEFEAT THE PUFF
100% TABATHA WOLFANG
REACH STAR LEVEL 20
COMPLETE ONE HAND MODE KUMA
UNLOCK HOMELESS CATS
UNLOCK MARY KATTY
DEFEATS CAT TOY
100% KUMA LUMA
REACH STAR LEVEL 15
COMPLETE ONE HAND MODE SHADOW
UNLOCK NORMAL LADY WHITESTROKE
UNLOCK TIFFANY RANCHO
100% SHADOW MOON
DEFEAT PUMPKIN
COMPLETE ONE HAND MODE NEKOS
PLAY WITH BEAR KING
REACH STAR LEVEL 10
DEFEAT THE CATNIP BOSS
100% DOUBLE NEKOS
PICK THE LASER POWER UP
PICK THE RAY POWER UP
PLAY WITH FOXXXY
UNLOCK KUMA LUMA
GET A PERFECT 5 HEARTS SCORE
COMPLETE ONE HAND MODE NORIKO
DESTROY THE MOTHERNIP MINIBOSS
UNLOCK SHADOW MOON
SKIP ONE OF OUR COMICS STYLED CUTSCENES
TAKE A PICTURE OF A LOST NEKO
DEFEAT NEKO BELL
YOU DIED IN A DATE
100% MIMI-CHAN
PICK THE GUN POWER UP
PICK THE MISSILE POWER UP
DESTROY THE X-NIP MINIBOSS
PICK THE SHIELD POWER UP
EXPLODE A PIECE OF CLOTH
PLAY WITH LEISURE LION
HAVE YOUR FIRST DATE
PRESS START
SEE THE CREDITS!
YOU ENTERED GALLERY MODE
UNLOCK TABATHA WOLFANG