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