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