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