Here is the full list of all 87 MINDNIGHT achievements.
Reach level 20
Own 5 skins
Win 20 games as an agent
Win a 6-man game in casual mode
Create a Custom Game
Win a 8-man game in casual mode
Win a game with the Cadet skin
Win a 7-man game in casual mode
Write 5000 words
Write 250 words in a single game
Win a game with the Lieutenant skin
Win 10 games as a hacker
Use the Thinking Emoji in a game
Be voted for all the missions of the game
Win 20 games
Win a 5-man game in casual mode
Win a game with the Ensign skin
Reach level 5
Reach level 10
Win 10 games as an agent
Win 5 games in a row
Win 5 games as a hacker
Win 10 games
Take part in all the missions of a game
Win a game by going on all missions
Win 5 games as an agent
Write 100 words in a single game
Win 5 games
Win a game by not going on a single mission
Win a game without losing a mission
Win a game as a hacker in the first 3 missions
Win 3 games in a row
Win 2 games in a row
Win a game
Agents win without the hackers taking part in any mission
Win the game with the last possible mission
Win 50 games
Win 100 games
Win 50 games as an agent
Win 100 games as an agent
Win 20 games as a hacker
Win 50 games as a hacker
Win 100 games as a hacker
Win 7 games in a row
Win 10 games in a row
Write 10000 words
Write 20000 words
Write 100 bad words
Write 500 bad words
Win as an agent in the last mission with a double fail in the missions before
Win as a hacker by reaching 5 node teams rejected
Win as an agent in the last voting round (before losing by skip)
Own 10 skins
Own 20 skins
Win a game with the Heckard skin
Win a game with the Lin Baden skin
Win a game with the Micky skin
Win a game with the Loolee skin
Win a game with the Suit Guy skin
Win a game with the Aloire of Satora skin
Win a game with the Chef skin
Win a game with the Ketchup skin
Win a game with the Hacker Man skin
Win a game with the Pierrot skin
Win a game with the Gha'Ben skin
Win a game with the McFly skin
Win a game with the Mandeer skin
Win a game with the Snowman skin
Win a game with the Santa skin
Win a game with the Lelaa skin
Win a game with the Shodan skin
Win a game with the Tuxedo Guy skin
Win a game with the Grim Reaper skin
Win a game with the Hangover John skin
Reach level 30
Win 500 games
Win 1000 games
Use the Surprised emoji in a game
Use the Straight Face emoji in a game
Use the Angry emoji in a game
Use the Kiss emoji in a game
Use the Cute emoji in a game