Here is the full list of all 69 DEEP SPACE WAIFU: FANTASY achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
COMPLETE ONE HAND OPHELIA
DEFEAT THE MOAI ANGEL
100% OPHELIA
COMPLETE ONE HAND SONJA
FIND THE CLITORIUS
DEFEAT BRAINHOLDER
100% SONJA DRAGONTOOTH
FIND A RANDOM ENCOUNTER
COMPLETE ONE HAND AUGEMEISTER
RESCUE THE PRINCESS FIERNA
EXPLORE ALL OF THE HENTALIA CONTINENT
100% AUGEMEISTER
COMPLETE ONE HAND RYA
UNLOCK OPHELIA
REACH STAR LEVEL 35
DEFEAT THE UGLY FAERIES
COMPLETE ONE HAND TIA SOFTHAND
UNLOCK THE SWORD ABILITY
UNLOCK AUGEMEISTER
100% NORMAL RYA TUTORIALICCA
DEFEAT THE KNIGHT SKULL
UNLOCK THE FILLED SPECIAL BAR
UNLOCK THE EXTRA SHOOTING POWER
COMPLETE ONE HAND ABYSSAL
UNLOCK SONJA DRAGONTOOTH
UNLOCK THE DRAGON
REACH STAR LEVEL 25
100% TIA SOFTHAND
DEFEAT SATAN
100% METAL ABYSSAL
COMPLETE ONE HAND MODE TRICCIA
DEFEAT ASMODEUS
100% TRICCIA
COMPLETE ONE HAND MODE OROCHI
UNLOCK THE EXTRA POWER UP SLOT
UNLOCK TRICCIA
UNLOCK THE UNICORN
REACH STAR LEVEL 15
DEFEATS TENTACLE MOON
100% OROCHI THE NAGA
DESTROY THE ANGEL MINIBOSS
COMPLETE ONE HAND MODE CARSSIA
100% CARSSIA BORGOTH
UNLOCK NORMAL RYA TUTORIALICCA
DEFEAT VIKING
COMPLETE ONE HAND MODE JELLY
UNLOCK THE BANDANA
UNLOCK THE PROTECTIVE HELMET
UNLOCK TIA SOFTHAND
UNLOCK METAL ABYSSAL
REACH STAR LEVEL 10
DEFEAT THE SLIME SUB BOSS
100% JELLY-CHAN
COMPLETE ONE HAND MODE RENA
UNLOCK OROCHI THE NAGA
UNLOCK CARSSIA BORGOTH
GET 5 STARS IN ONE STAGE
SKIP ONE OF OUR EMOTIONAL CUTSCENES
TAKE A PICTURE OF A GIRL IN MIDDLE AGES
DEFEAT THE DEVILANGEL SUB BOSS
100% RENA GREENLEAF
REACH STAR LEVEL 5
DESTROY THE DEVIL MINIBOSS
YOU DIED IN A DATE
EXPLODE A PIECE OF CLOTH
HAVE YOUR FIRST DATE
PRESS START
SEE THE CREDITS!
YOU ENTERED GALLERY MODE