Here is the full list of all 11 Hate Plus achievements.
Take an actual honest-to-god IRL photograph of the cake you're sharing with *Hyun-ae, and e-mail it to the developer! cake@hateplus.com
Finish the game with your completely impossible AI harem!
Complete all three routes over the span of nine real days without skipping, LIKE YOU'RE SUPPOSED TO, GEEZE.
Finish the game with the security AI in a default uniform, New *Mute!
Read every log file again with *Mute on day three.
Finish your mission by arriving on Earth.
Finish the game with your cute AI wife and/or completely platonic friend *Hyun-ae!
LOL SPOILERS *MUTE DIES
Finish the first day of any route.
Finish the game with the security AI in traditional dress, *Mute!
Start *Mute's route and finish, as both a man and a woman.