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