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.
Start *Mute's route and finish, as both a man and a woman.
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!