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