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 30 challenges.
Encounter an Agent of the Nine somewhere in the system.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete a Nightfall strike.
Complete a Heroic public event.
Complete Introduction: Crucible.
Reach level 20.
Acquire each Hunter subclass.
Acquire each Titan subclass.
Acquire each Warlock subclass.
Complete the Leviathan raid.
Complete the Leviathan raid on Prestige difficulty.
Earn 5,000 Triumph points.
Enter the Dreaming City.
Complete a Forsaken Exotic Quest.
Defeat a Forsaken Nightfall Boss.
Win a Gambit match.
Collect 10 Forsaken Exotic weapons or armor.
Complete a Triumph Seal.
Complete a Collections Badge.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Complete the "Last Wish" Raid.