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.
Acquire each Titan subclass.
Acquire each Warlock subclass.
Complete 30 challenges.
Collect 15 Red War exotic weapons or armor.
Encounter an Agent of the Nine somewhere in the system.
Complete Introduction: Crucible.
Complete a Nightfall strike.
Complete a Heroic public event.
Reach level 20.
Acquire each Hunter subclass.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete the Leviathan raid.
Complete the Leviathan raid on Prestige difficulty.
Win a Gambit match.
Complete a Collections Badge.
Enter the Dreaming City.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Earn 5,000 Triumph points.
Collect 10 Forsaken Exotic weapons or armor.
Complete a Triumph Seal.
Complete a Forsaken Exotic Quest.
Defeat a Forsaken Nightfall Boss.
Complete the "Last Wish" Raid.