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