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