Here is the full list of all 85 Legend of Feather achievements.
Any character reaches Level 5 in the adventure
Any character reaches Level 10 in the adventure
Any character reaches Level 20 in the Bluestone Beach
Any character reaches Level 40 in Tianli Grassland
Any character reaches Level 60 in Ancient Wasteland
Any character can survive for 1 minute in the adventure
Any character can survive for 5 minutes in the adventure
Any character can survive for 10 minutes in the adventure
Any character can survive for 15 minute in the adventure
Huang Xu survives for 5 minutes
Qinqin survives for 10 minutes
Yan Zhuo survives for 10 minutes
Shi Kui survived for 10 minutes
Mao Yue survived for 15 minutes
Xuan Ling survived for 15 minutes
Yang Shuo survived for 15 minutes
Upgrade Bamboo Flute to Level 4
Upgrade Circle to Level 4
Upgrade Spirit Lamp to Level 7
Upgrade Fan to Level 7
Upgrade Zen Tomahawk to Level 7
Upgrade Long Staff to Level 7
Upgrade Umbrella to Level 7
Upgrade Blade to Level 7
Upgrade Two-Handed Swords to Level 7
Upgrade Iron Spear to Level 7
Upgrade Iron Mace to Level 7
Upgrade Sword to Level 7
Found a Calabash
Found a Cryolite
Kill 5000 monsters in total
Kill 50000 monsters in total
Kill 100000 monsters in total
Dig 5 ores
Open 5 Iron Chest
Equip 6 different weapons at the same time
Found a Amulet
Get 6000G at one time during the adventure
Unlock 45 favorites
Unlock 55 favorites
Unlock 65 favorites
First death
Defeat Sealord
Defeat Big-Egg monster
Defeat Putuo Buddha
Defeat Refining Beast
Defeat Mani King
Defeat Mani Knight King
Get Lei Yingjian
Get Tianyin Yuxiao
Get Purple Lightning
Get the Dragon Stick
Get the Demon Subduing Mace
Get the Qiankun Circle
Get Thunderbolt Halberd
Get Demon Extinguish
Get JinWu Fan
Get Bloody Blade
Get Hunyuan Umbrella
Get SummoningSpirit Lamp
Get Red Lotus
Get Hexagonal Dart
Find the Wind Fire Wheel
Defeat Gongsun Yin at Bluestone Beach
Upgrade Wind Pearl to Level 3
Upgrade Armor to Level 5
Defeat a sea princess [elite monster]
Get Rosy Clouds
Find the village head's leather drum
Get Jinwuleidi
Find the Faramita Feathers
Find the Devil Fragment
Defeat WenLin
Yan Zhuo reaches level 99
Xuan Ling reaches level 99
Shi Kui reaches level 99
Yu Rou reaches level 99
Yi Shuang reaches level 99
Defeat Golden Spirit
Find the Fire Staff
Find the Ice Staff
Get Ice&Fire
Get Ghost Cone
Get Sanzen Sekai
Get Liucaifeixia