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