Here is the full list of all 31 Infernal: Hell's Vengeance achievements worth 1,000 gamerscore.
Complete game in hard difficulty
Complete game in medium difficulty
Complete game in easy difficulty
Complete Mission 5
Find the Observatory
Complete mission 4
Find Barbara
Find the device in the plane
Don't activate the gas traps in the plane
Find the plane
Complete mission 3
Enter the Steelworks
Obtain multiple Teleportation power
Complete mission 2
Find Wolf's lab
Defeat Elena
Find Elena
Fire rocket launcher 20 times
Find 3 health boosters to increase your health
Find Dual Pistol
Complete mission 1
Retrieve energy from 100 enemies
Use infernal powers 100 times
Survive the upper cloister
Find 3 mana boosters to increase your mana
Get to the upper cloister
Obtain Teleportation power
Get inside the cloister
Obtain Infernal power
Join the Abyss
Complete Prologue