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 the ANNA level.
Complete the KHAN level.
Complete the PAVEL level.
Open 10 locked safe boxes.
Complete the SPIDER LAIR level.
Complete the SNIPER TEAM level.
Disarm 10 Traps.
Free the Prisoners.
Kill the Watchmen attacking the Railcar without taking any damage.
Rescue the Women and Children on the BANDITS level without raising alarm.
Complete the BRIDGE level without a kill.
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.
Remove your mask when Lesnitsky demands it.
Kill the Rhino.
Burn 50 Cobwebs.
Kill 100 Mutants.
Spend 30 minutes' worth of Filters.
Find and return the crying child's Teddy Bear.
Drink at every occasion.
Turn off 40 Lights without breaking them.
Kill 100 Human Enemies.
Kill 10 enemies in a row with Throwing Knives.
Use 10 Lever Switches.
Escape from the Red Line.
Watch the entire Theater Show.
Complete the ECHOES level undetected by the Watchmen.
Make 10 Spiders flip belly-up.
Stealthily kill 15 Enemies.
Escape the chasing Nazis on the REICH level without being caught once.
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.
Kill all armed enemies on the REVOLUTION level, including all reinforcements.
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.
Complete all 43 of Artyom's hidden Diary pages.
Save D6.
Complete the game in Survival Mode.
Complete the KSHATRIYA level.
Complete the TOWER level.
Spend 1 hour on the DEVELOPER level.