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