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