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