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