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