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