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