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