Here is the full list of all 69 Dragon Age Inquisition achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Craft a weapon or piece of armor in single-player mode.
Find and recover a shard identified by an ocularum.
Discover a campsite and establish an Inquisition camp in any wilderness area.
Upgrade any ability once in single-player mode.
Complete a timed mission on the war table.
Enchant or upgrade a piece of equipment in single-player mode.
Finish the prologue.
Trigger a cross-class combo with a character you control in single-player mode.
Close the Breach.
Survive an attack on the Inquisition.
Make an impression on the Orlesian court.
Face your fears in the Fade.
Reach an ancient ruin before your enemies.
Recruit a powerful ally to even the score.
End the threat once and for all.
Recruit all possible companions in a single playthrough.
Commit to a romantic relationship.
Recruit a new companion.
Gain access to a major city for the Inquisition.
Purchase or secure five different mounts of any kind.
Discover a veilfire rune.
Choose a specialization class.
Secure a mount.
Harvest 50 herbs from Skyhold's garden in a single playthrough.
Kill a high dragon in single-player mode.
Purchase any new decoration element for Skyhold.
Gain the full approval of the Orlesian court.
Land a single blow in excess of 1,000 damage in single-player mode.
Craft an item from Tier 4 materials in all non-masterwork slots in single-player mode.
Upgrade your alchemic potions, grenades, or tonics 30 times in a single playthrough.
Slay 10 high dragons in single-player mode.
Finish the single-player campaign on at least Hard without lowering the difficulty.
Finish the single-player campaign on Nightmare without lowering the difficulty.
Unlock 15 astrariums in a single playthrough.
Spend 10 points in a single ability tree with any one single-player character.
Earn 50,000 or more gold across all single-player playthroughs.
Enter the heart of the Solasan temple.
Discover a campsite and establish at least one Inquisition camp in 10 wilderness areas.
Liberate three keeps in a single playthrough.
Complete 50 missions or operations in a single playthrough.
Completely upgrade one throne.
Acquire 10 Inquisition agents in a single playthrough.
Reach level 20 in single-player mode.
Level up the Inquisition to rank 10.
Become friends with at least three of your inner circle in one playthrough.
Collect 250 codex entries in a single playthrough.
Defeat 1,000 demons in single-player mode.
Defeat 2,500 enemies in single-player mode.
Complete 20 requisition requests in a single playthrough.
Seal 75 rifts in a single playthrough.
Destroy all the Winter Shards and light all the fires in the Old Temple.
Impress the Avvar of Stone-Bear Hold and gain their friendship.
Uncover the secrets of a legendary figure.
Dispel a myth of ancient days.
Complete a mission at the expedition table in the Legion of the Dead camp.
Defeat an ogre alpha.
Help Shaper Valta discover secret dwarven history.
End the earthquakes threatening the surface.
Slay 10 great bears promoted by Grizzly End.
Rest Easy trial always on in Emprise du Lion: claim Suledin Keep.
Travel Light on for "In Hushed Whispers": finish the quest.
Rub Some Dirt on It on: slay the Hivernal high dragon.
Defeat 20 foes promoted by Walk Softly.
Even Ground on: slay a level 16 or higher Fereldan Frostback.
Take It Slow on: reach Skyhold at level 5 or less.
Fair-Weather Friends always on: enter Halamshiral with all followers.
Progress the story to unlock.
Unlock all caches watched over by ancient statues.
Find all of the wearable items that make up the Taken Shape.