Here is the full list of all 50 The Legend of Spyro: Dawn of the Dragon achievements worth 1,000 gamerscore.
Complete the Catacombs
Complete the Twilight Falls
Complete the Valley of Avalar
Complete the City of Warfang
Complete Dragon City Golem
Complete the Underground Ruins
Complete the Dragon Dam
Complete the Destroyer
Complete the Burned Lands
Complete the Floating Islands
Complete Malefor's Lair
Complete the game a 100%
Upgrade all your elements to Max Level
Complete the game with at least 90% of the time in 2 Players Mode
Complete one Armor Set
Complete all Armor Sets
Bring the Artilleryman back to his catapult in less than 5 minutes
Kill 225 Grublins
Kill 450 Grublins
Kill 100 Orcs
Kill 200 Orcs
Close Warfang Gate without dying once
Kill 10 Trolls
Kill 45 Wyverns
Kill 70 Shadows
Upgrade one element to Max Level
Find all Elemental Upgrades
Kill all Elite Enemies
Perform 100 Enemy Grabs
Perform 100 Enemy Air Grabs
Throw 200 Enemies into the Air
Perform a 70 hit Combo string
Perform a 125 hit Combo string
Perform a 300 hit Combo string
Dodge all Golem attacks in Chamber of Retribution
Find all Health Upgrades
Launch 20 Fury attacks
Protect all the Cheetah's houses in the village
Eliminate 75 Enemies with a Fire attack
Eliminate 75 Enemies with an Electric attack
Eliminate 75 Enemies with a Wind attack
Eliminate 75 Enemies with a Poison attack
Eliminate 75 Enemies with an Ice attack
Eliminate 75 Enemies with a Fear attack
Kill 625 Enemies
Kill 1000 Enemies
Find all XP Crystals
Unlocked all Bonus galleries
Kill the Golem without dying once
Kill Malefor without dying once