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.
Complete a Nightfall strike.
Reach level 20.
Acquire each Titan subclass.
Complete Introduction: Crucible.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete a Heroic public event.
Collect 15 Red War exotic weapons or armor.
Complete 30 challenges.
Encounter an Agent of the Nine somewhere in the system.
Acquire each Hunter 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.
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.
Defeat a Forsaken Nightfall Boss.
Complete the "Last Wish" Raid.