Here is the full list of all 75 Halo Wars: Definitive Edition achievements.
Score the winning point in a game of Keepaway against Legendary AI's.
Win and never trail in a Tug of War game.
Disrupt 5 active Leader Powers in a single game on Blood River.
Win a 3v3 Skirmish game with 2 AI Allies.
Get a Scarab during a Reinforcement game.
Finish with 5000 net resources tributed to your teammates on Memorial Basin except in Deathmatch.
Kill 20 enemy squads with a continuous Covenant Leader Power on Memorial Basin.
Obtain a lifetime campaign Score over 1,000,000.
Finish all missions under Par Time on Heroic difficulty.
Get a Gold Medal with all Debuff Skulls Active.
Get a Gold Medal on every Campaign Mission.
Mission 1: Ram and kill 50 Grunts with Warthogs.
Mission 2: Destroy every Methane Tank.
Mission 3: Kill at least 5 Covenant Units with the Bridge.
Mission 4: Save Adam.
Mission 5: Jack 6 Covenant Vehicles.
Mission 6: Successfully protect every Rhino.
Mission 7: Do not destroy any Power Node.
Mission 8: Use Elephants to train 100 infantry.
Mission 9: Put every Colony in Hibernation Mode at the same time.
Mission 10: Distrupt all Tractor Beams.
Mission 11: Save all the Airlocks.
Mission 12: Repair the Power Core in less than 4 minutes.
Mission 13: Destroy 25 units with the Scarab.
Mission 14: Don't claim an extra base.
Mission 15: Open the Doors in order.
Collect all Skulls.
100% Completion.
Finish five missions under Par Time on Heroic difficulty.
Collect 8 Skulls.
Win a Heroic Skirmish Game against the AI in under 10 minutes.
Get a winning High Score with 10 or less Squads against the Heroic AI.
Finish one mission under Par Time on Heroic difficulty.
Get a Gold Medal on any mission.
Complete any Campaign Mission in Co-op Mode.
Win 10 Skirmish or Multiplayer Matches
Win 20 Skirmish or Multiplayer Matches
Win 30 Skirmish or Multiplayer Matches
Win 40 Skirmish or Multiplayer Matches.
Win 50 Skirmish or Multiplayer Matches.
Win 100 Skirmish or Multiplayer Matches.
Win 75 Skirmish or Multiplayer Matches.
Collect your first Skull.
Improve your Score in any Campaign Mission.
Win a Skirmish Game with every Leader.
Get 20,000 points in any Skirmish Game.
Use one of the 6 Major Leader Powers to destroy an enemy's last unit.
Win a Public game.
Win and have the highest score in a Public Game.
Gain at Least 15 population from a single wave in a Reinforcement game.
Hot drop 50 squads to your Covenant Leader in a single game on Barrens.
Unlock All Timeline Events.
Unlock 20 Timeline Events.
Win a game on every Skirmish Map.
Win a game in every Skirmish Game Mode.
Win a Skirmish Game with Dual Scarabs.
Unlock a Timeline Event.
Complete the Campaign on Heroic Difficulty.
Complete the Campaign on Legendary Difficulty.
Play Halo Wars for at least 24 Total hours.
Completed Mission 1 on any difficulty.
Completed Mission 2 on any difficulty.
Completed Mission 3 on any difficulty.
Completed Mission 4 on any difficulty.
Completed Mission 5 on any difficulty.
Completed Mission 6 on any difficulty.
Completed Mission 7 on any difficulty.
Completed Mission 8 on any difficulty.
Completed Mission 9 on any difficulty.
Completed Mission 10 on any difficulty.
Completed Mission 11 on any difficulty.
Completed Mission 12 on any difficulty.
Completed Mission 13 on any difficulty.
Completed Mission 14 on any difficulty.
Completed Mission 15 on any difficulty.