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