Here is the full list of all 49 Metro 2033 Redux achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Wipe your Gas Mask 20 times.
Help the poor, a coin for the kid, medicine for the sick. You help everyone you see.
Kill 50 humans with pneumatic weapons.
Kill 100 enemies using revolvers.
Blow up the tunnel and airlock at CURSED STATION.
On the level OUTPOST reach the radio tower and broadcast the commander's message.
Find the truth.
Kill 20 lurkers.
Kill 30 enemies with flame grenades.
Kill 100 enemies with shotguns.
Kill a librarian.
On the level FRONTLINE kill all of the enemy Red Army and Fascist Soldiers.
Kill 200 Mutants.
Kill 2 demons.
Complete FRONTLINE level without killing anyone.
Explode 30 enemies.
Spend 60 seconds in a Radiation Hotspot.
Kill 100 enemies with assault rifles.
Drink at every occasion.
Complete the level BLACK STATION without killing or knocking out any enemies.
Make 30 deals in weapon shops.
Stealthily kill 15 Enemies.
Kill 30 enemies with throwing knives.
Kill 100 nosalises.
Kill 5 amoebas.
Complete all 51 of Artyom's hidden Diary pages.
Kill 30 enemies with a flamethrower.
On the level HUNTER kill the nosalises before they break through the ventilation grilles.
On the level DEPOT silently kill the first guard and break into the Fascist station unnoticed.
Find all Ranger stashes in Dead City.
Save a group of Reds from Fascist captivity.
Open 15 locked safe boxes.
Save 1000 military-grade rounds.
Get 30 kills with Hellbreath.
Kill 30 human enemies in close combat.
Kill 30 human enemies with headshots.
Kill 15 human enemies with Headshots from at least 30 meters' distance.
Disarm 15 wire traps.
Complete the game in Spartan Mode.
Kill 10 Spiders.
Knock 30 human enemies out in close combat.
Complete the game in Survival Mode.
Kill 10 Enemies in a row without taking any damage.
Use a Medkit 75 times.
Become a true ranger.
Kill 100 Human Enemies.
Kill 50 Watchmen.
Kill at least one enemy with each weapon available in the game
Exchange 500 Military-Grade 5.45 rounds at Exchange kiosks.