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