Here is the full list of all 38 HELLDIVERS 2 achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Defeat a Hulk.
Complete 10 tactical objectives.
Extract after the timer reaches zero.
Kill 25 enemies with one stratagem.
Fly at least 25 meters from the shockwave of an explosion.
Complete a Stalker Hive tactical objective.
Kill a bug warrior with a shotgun within 1 meter.
Kill a target at a distance of over 100m.
Complete a mission but fail to extract.
Provide assisted reload for a teammate.
Extract with a full team on a Hard difficulty or more mission.
Customize your Helldiver with new cape, armor, and helmet.
Extract from a mission during nighttime.
Play 1 Bug Mission.
Play 1 Bot Mission.
Play a planet defense mission.
Kill 150 enemies during the same mission.
Complete Basic Training.
Complete an Extreme difficulty mission or higher without anyone dying.
Complete a full Hard difficulty mission or higher without anyone firing their primary or support weapon.
Complete a full Extreme difficulty Blitz mission and extract in under 6 minutes.
Kill a Charger with a resupply pod.
Extract at least 15 rare samples from a mission as a team.
Complete at least 100 missions.
Have 6 orbital barrage stratagems in the same place at the same time.
Kill 5,000 enemies.
Kill 100 enemies using fire damage during the same mission.
Fire at least 150 rounds in one burst, killing at least 10 enemies.
Be injured in all limbs at the same time.
Reach max level on one ship module.
Upgrade all ship modules at least 1 level.
Defeat a Bile Titan
Shoot off both arms on a Hulk and then extract while it's alive.
Throw back a live grenade.
Play at least 50 missions.
While using a jump pack, knock yourself into a ragdoll state.
Heal another player using stims.
Extract with at least 15 common samples.