Halo Wars: Definitive Edition achievements

Gain at Least 15 population from a single wave in a Reinforcement game.

Collect 8 Skulls.

Mission 2: Destroy every Methane Tank.

Win 10 Skirmish or Multiplayer Matches

Finish five missions under Par Time on Heroic difficulty.

Win a Skirmish Game with Dual Scarabs.

Mission 6: Successfully protect every Rhino.

Win a 3v3 Skirmish game with 2 AI Allies.

Win and have the highest score in a Public Game.

Mission 15: Open the Doors in order.

Use one of the 6 Major Leader Powers to destroy an enemy's last unit.

Win a Public game.