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