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