Here is the full list of all 39 Gal*Gun: Double Peace achievements.
Unlock All Trophies
View the True Love Route's True Ending
View All of the True Endings
Obtain All Images in the Gallery
Complete Profiles for Every Girl
View Patako's True Ending
Receive a “Perfect!” Score VS Patako
View Kurona's True Ending
Defeat 100 Demon Girls
Receive a “Perfect!” Score VS Ekoro
Receive a “Perfect!” Score VS Kurona
View Maya's True Ending
Receive a “Perfect!” Score VS Mr. Demon Balloon
Get a Perfect Score on “Maya's Medical Care”
View Aoi's Ending
Achieve Godlike Rank
View Shinobu's True Ending
View Sisters Route's True Ending
Receive a “Perfect!” Score VS Shinobu & Maya
Get a Perfect Score on “Demon-Attracting Balm”
Collect All of the Panties From the Changing Room
Get a Perfect Score on “Sisters' Odd Ritual”
View Ekoro's True Ending
Receive a “Perfect!” Score VS Shinobu
Receive a “Perfect!” Score VS Mr. Demon Veggie
Fulfill 10 of the Girls' Requests
Make 50+ Girls Experience “Double Peace”
Get a Perfect Score on “Her Majesty Shinobu”
Get a Perfect Score on “Shinobu in the Window”
View Your First Ending
Experience Your First Final Doki-Doki Mode
Receive a “Perfect!” Score VS Maya
Give 500 Girls Euphoria
Fire 1000 Pheromone Shots
Get a Perfect Score on “Maya's Demon Calling”
Get 100 Ecstasy Shots
Get a 30 Combo of Ecstasy Shots
Experience Your First Doki-Doki Mode
Give a Girl Euphoria