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