Full list of all 23 Destiny 2 achievements. It takes around 200 hours to unlock all of the achievements in the base game on Windows.
The base game contains 13 achievements, and there is 1 DLC pack containing 10 achievements.
Collect 15 Red War exotic weapons or armor.
Complete a Nightfall strike.
Reach level 20.
Acquire each Titan subclass.
Complete a Heroic public event.
Acquire each Hunter subclass.
Acquire each Warlock subclass.
Complete Introduction: Crucible.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete 30 challenges.
Complete the Leviathan raid.
Complete the Leviathan raid on Prestige difficulty.
Encounter an Agent of the Nine somewhere in the system.
Enter the Dreaming City.
Earn 5,000 Triumph points.
Win a Gambit match.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Collect 10 Forsaken Exotic weapons or armor.
Complete a Triumph Seal.
Complete a Collections Badge.
Complete a Forsaken Exotic Quest.
Defeat a Forsaken Nightfall Boss.
Complete the "Last Wish" Raid.