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.
Complete the KSHATRIYA level.
Kill the Watchmen attacking the Railcar without taking any damage.
Complete the BRIDGE level without a kill.
Complete the SNIPER TEAM level.
Complete the HEAVY SQUAD level.
Complete the SPIDER LAIR level.
Spend 1 hour on the DEVELOPER level.
Complete the PAVEL level.
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.
Destroy D6.
Complete the game in Spartan Mode.
Complete all 43 of Artyom's hidden Diary pages.
Kill Pavel.
Remove your mask when Lesnitsky demands it.
Rescue the Women and Children on the BANDITS level without raising alarm.
Open 10 locked safe boxes.
Kill all armed enemies on the REVOLUTION level, including all reinforcements.
Kill 10 enemies in a row with Throwing Knives.
Complete the KHAN 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.
See all Visions in the Dead City.
Disarm 10 Traps.
Find out about the Reds' plans.
Stealthily kill 15 Enemies.
Kill the Rhino.
Find and return the crying child's Teddy Bear.
Drink at every occasion.
Kill 100 Mutants.
Turn off 40 Lights without breaking them.
Spend 30 minutes' worth of Filters.
Make 10 Spiders flip belly-up.
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.
Burn 50 Cobwebs.
Choose three primary weapons that use different ammo.
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.