Full list of all 47 Exit the Gungeon achievements. It takes around 30-35 hours to unlock all of the achievements in the base game on Windows.
The base game contains 44 achievements, and there is 1 DLC pack containing 3 achievements.
Mastered The Deathvator.
Upgraded Bello's Stools.
Rescued All Npcs From The Cell.
Aced Winchester's Game.
Completed Level 5 Boss Without Taking Damage.
Mastered The Bolt Python.
Reached Max Combo.
Exited The Gungeon As The Cultist.
Mastered The Kill Shrine.
Mastered Gungamesh.
Exited The Gungeon As The Robot.
Mastered The Armored Beholster.
Unlocked All Characters.
Exited The Gungeon As The Hunter.
Mastered The Lich Dragun.
Exited The Gungeon As The Marine.
Exited The Gungeon As The Bullet.
Completed Level 3 Boss Without Taking Damage.
Mastered The Chamber Of Flame.
Mastered The High Priest Past.
Mastered The Coltaur.
Mastered The Medusalier.
Bought Something From Cadence And Ox.
Mastered The Meowitzer.
Exited The Gungeon As The Convict.
Achieved Beast Mode Level 2.
Bought Something From Bello.
Accessed All Elevator Types.
Mastered The Mecha Bullet.
Completed Level 2 Boss Without Taking Damage.
Mastered His Majesty's Chancellor.
Successfully Exited The Gungeon.
Exited The Gungeon As The Pilot.
Completed Level 4 Boss Without Taking Damage.
Completed Manuel's Test, A Great Achievement.
Completed Level 1 Boss Without Taking Damage.
Aced Just Dessert Golf.
Bought All Hats.
Bought All Skins.
Helped Flynt Avoid Embarassment.
Helped Goopton With Something Personal.
Sated Daisuke's Craving.
Gave The Old Man Something To Fiddle With.
Reunited Old Red with Daisy.
Mastered The Glocktopus.
Aced Helmet Kick.
Carried Eight Weapons At Once.