Here is the full list of all 49 Metro: Last Light Redux achievements. It takes around 30-35 hours to unlock all of the achievements on Windows.
Save D6.
Open 10 locked safe boxes.
Remove your mask when Lesnitsky demands it.
Complete the FACILITY level without killing or raising alarm.
Kill the Watchmen attacking the Railcar without taking any damage.
Kill all armed enemies on the REVOLUTION level, including all reinforcements.
Drink at every occasion.
Complete the game in Spartan Mode.
Complete all 43 of Artyom's hidden Diary pages.
See all Visions in the Dead City.
Complete the BRIDGE level without a kill.
Find and return the crying child's Teddy Bear.
Complete the REVOLUTION level without killing and raising an alarm.
Kill 10 enemies in a row with Throwing Knives.
Watch the entire Theater Show.
Finish the ASHES level without taking a hit.
Spend 1 hour on the DEVELOPER level.
Complete the TOWER level.
Complete the SNIPER TEAM level.
Complete the KSHATRIYA level.
Disarm 10 Traps.
Complete the SPIDER LAIR level.
Burn 50 Cobwebs.
Complete the PAVEL level.
Complete the KHAN level.
Complete the SEPARATION level without killing or raising alarm.
Complete the ANNA level.
Complete the HEAVY SQUAD level.
Destroy D6.
Complete the game in Survival Mode.
Make Moskvin tell the truth with help from the Dark One.
Save the Bear from the Watchmen after the fight.
Kill Pavel.
Find out about the Reds' plans.
Kill the Rhino.
Turn off 40 Lights without breaking them.
Kill 100 Mutants.
Rescue the Women and Children on the BANDITS level without raising alarm.
Spend 30 minutes' worth of Filters.
Make 10 Spiders flip belly-up.
Kill 100 Human Enemies.
Escape from the Red Line.
Complete the ECHOES level undetected by the Watchmen.
Use 10 Lever Switches.
Stealthily kill 15 Enemies.
Escape the chasing Nazis on the REICH level without being caught once.
Free the Prisoners.
Complete training sequence.
Choose three primary weapons that use different ammo.