Here is the full list of all 39 HELLDIVERS achievements.
Achieve the rank of Sergeant (Rank 7).
Kill 7 enemies within a very short time using only your primary weapon.
Do 25 capespins in a row, without moving, while on the ship bridge.
Customize your character.
Complete a volcanic type planet of difficulty 5 or more.
Complete a mission.
Complete a difficulty 10 or higher mission without a single death.
Kill 100,000 enemies.
Complete at least one planet in a successful Galactic Campaign.
Kill a Bug or Illuminate assassination target by running it over with the APC or HAV.
Achieve the rank of Grand Lord (Rank 25).
Kill a Bug Tank with a Resupply Stratagem Hellpod.
Take part in a successful defense of a capital city by completing at least one mission.
Extract from a difficulty 8 or higher mission with 4 players where all 4 get on the shuttle.
Use the Reinforce Stratagem while downed and the last Helldiver alive on a difficulty 8 or higher mission with 4 players.
Complete a difficulty 4 or higher mission in 5 minutes or less.
Kill 10,000 enemies.
Achieve the rank of Captain (Rank 13).
Take part in a successful final assault on an enemy's home planet by completing at least one mission.
Complete all missions on a planet with difficulty 10 or higher.
Complete a difficulty 7 or higher mission without triggering any alarms.
Successfully complete an escort objective where all 4 NPCs survive.
Complete a difficulty 7 or higher mission against the Cyborgs without taking damage from any enemy.
Complete a mission using only Stratagems.
Complete a mission with over 300 shots fired and 80% accuracy or better.
Join another game through the matchmaking system.
In a 4 player game, on a Friday, have all players sitting in an APC or HAV at the same time.
Play at least once against all enemy races.
Play at least once on a desert, a forest, and a snow planet.
Finish the Training.
Destroy a Bug Nest, Cyborg AA, or Illuminate Beacon with anything but the NUX-223 Hellbomb.
Fully upgrade all non DLC Weapons and Stratagems.
Kill a Bug Tank, Bug Behemoth, or Cyborg IFV by having the extraction shuttle land on it.
Face each new enemy once.
While in melee range from a Cyborg Warlord, use the "NO" communication command.
Kill an Illuminate Obelisk while it is closed.
Defeat a Bug Hive Lord.
Defeat a Cyborg Siegemech.
Defeat an Illuminate Great Eye.