Here is the full list of all 22 Etrian Odyssey HD achievements.
Defeated an Yggdrasil Bud, Yggdrasil Sprout, and Yggdrasil Clover.
Obtained more than 250,000 Ental.
Defeated the Dragon.
Defeated the Drake.
Defeated the Wyrm.
Reached the Sixth Stratum.
Defeated the Etreant.
Reached the Fifth Stratum.
Unlocked the Hexer class.
Reached the Fourth Stratum.
Retired an adventurer.
Let an adventurer rest.
Unlocked the Ronin class.
Completed the quest "The bandit's treasure".
Defeated a boss in a single turn.
Dealt 1,000 damage with a single hit.
Reached the Third Stratum.
Reached the Second Stratum.
Reached the First Stratum.
Obtained all other achievements.
Defeated the boss of the Sixth Stratum on Expert difficulty.
Defeated the Yggdrasil Core.