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.
Complete the game in Spartan Mode.
Kill 2 demons.
Kill 5 amoebas.
Kill 10 Spiders.
Use a Medkit 75 times.
Wipe your Gas Mask 20 times.
Kill a librarian.
Kill 50 Watchmen.
Kill 30 human enemies with headshots.
Kill 200 Mutants.
Kill 20 lurkers.
Kill 10 Enemies in a row without taking any damage.
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.
Blow up the tunnel and airlock at CURSED STATION.
Kill 100 nosalises.
Kill 100 enemies with shotguns.
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.
On the level OUTPOST reach the radio tower and broadcast the commander's message.
Find the truth.
Kill 30 enemies with flame grenades.
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.
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.
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.
Find all Ranger stashes in Dead City.
Open 15 locked safe boxes.
Save 1000 military-grade rounds.
Get 30 kills with Hellbreath.
Kill 30 human enemies in close combat.
Kill 15 human enemies with Headshots from at least 30 meters' distance.
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.