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