Here is the full list of all 41 NIER achievements worth 1,000 gamerscore. It takes around 60-80 hours to unlock all of the achievements on Xbox 360.
You successfully cultivated the legendary flower.
You viewed the fourth ending (Ending D).
Defeat someone you care for within three and a half minutes.
You viewed the third ending (Ending C).
You killed 100 sheep.
You caught a rhizodont.
You caught one of every type of fish.
You completed the game within fifteen hours.
Defeat the Shade inside you within three and a half minutes.
Defeat the betrayers again within three and a half minutes.
Defeat Roc within three and a half minutes.
You viewed the second ending (Ending B).
Destroy the world-saving tome within one and a half minutes.
Defeat the betrayers within two and a half minutes.
Find every weapon.
Defeat Wendy within eight and a half minutes.
You upgraded 5 weapons to their maximum level.
Collect 50 percent of all words.
Defeat Gretel within two and a half minutes.
Defeat a berserking Shade within one minute.
Pull off a 100-hit combo.
Read the final novel segment.
You viewed the first ending (Ending A).
You defeated the Shadowlord.
Defeat Goose within two minutes.
You unlocked the key to the Shadowlord's castle.
Defeat P-33 within four and a half minutes.
You freed Kainé from her petrification.
Emil joined your party.
Complete 30 quests.
Learn every type of magic.
Complete 20 quests.
You collected 50 types of raw materials.
Kainé joined your party.
Complete 10 quests.
You rode a boar for at least five minutes.
Grimoire Weiss joined your party.
Pull off a 50-hit combo.
Accumulate 1,000,000 pieces of gold.
Upgrade 15 weapons to their maximum level.
Upgrade 30 weapons to their maximum level.