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.
Complete the game in Survival Mode.
Save D6.
Complete all 43 of Artyom's hidden Diary pages.
Remove your mask when Lesnitsky demands it.
Finish the ASHES level without taking a hit.
Kill all armed enemies on the REVOLUTION level, including all reinforcements.
Complete the REVOLUTION level without killing and raising an alarm.
Complete the TOWER level.
Complete the SPIDER LAIR level.
Spend 1 hour on the DEVELOPER level.
Kill the Watchmen attacking the Railcar without taking any damage.
Complete the FACILITY level without killing or raising alarm.
Complete the BRIDGE level without a kill.
Complete the SEPARATION level without killing or raising alarm.
Complete the ANNA level.
Complete the KHAN level.
Complete the PAVEL level.
Open 10 locked safe boxes.
Complete the SNIPER TEAM level.
Complete the KSHATRIYA level.
Complete the HEAVY SQUAD level.
Destroy D6.
Complete the game in Spartan Mode.
Make Moskvin tell the truth with help from the Dark One.
Save the Bear from the Watchmen after the fight.
Kill Pavel.
See all Visions in the Dead City.
Find out about the Reds' plans.
Disarm 10 Traps.
Kill the Rhino.
Kill 100 Mutants.
Turn off 40 Lights without breaking them.
Find and return the crying child's Teddy Bear.
Drink at every occasion.
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.
Kill 10 enemies in a row with Throwing Knives.
Escape from the Red Line.
Watch the entire Theater Show.
Burn 50 Cobwebs.
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.