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