- Unlike Metro 2033, you can buy filters after the early game, and the ones you find out in the open are actually useful.
- Artyom will automatically switch filters when one runs out completely. The only reason to switch manually is if you hate listening to choking noises / if you suspect hostiles are nearby and don't need the distraction.
- You will find a LOT of upgraded weapons during gameplay, and you should only upgrade the ones you really, really like.
- The "Bandits" chapter is the only one with both a merchant and enemies to fight - this means that if you're patient, you can earn a ton of extra money by swapping your weapons with the ones your enemies were carrying, backtracking to the beginning, selling them, then repeating. It can take awhile, but it's worth it - on non-Ranger modes each gun can sell for 100+, which should leave you with more than enough bullets to last you the rest of the game.
- There are two big difficulty spikes in the game, and they both involve defending your position while waiting for something to arrive. Don't worry if you are getting killed all the time, the difficulty evens out after those parts.
- Don't underestimate the Nosalis. They got a pretty huge buff from 2033.
- Wait for the last ten/twenty seconds of air before swapping filters.
- The Throwing Knives are incredibly overpowered, and you can retrieve them.
- Ranger Mode is not necessary, the difficulty levels are properly balanced. It's not like 2033 where Easy made everything a bullet sponge.
- If you are using an AMD card, turn off PhysX which is enabled by default. Your framerate will thank you.
- The Kshatriya mission in the "Factions" DLC is the closest we have to S.T.A.L.K.E.R in the Metro engine for now. It's really good.
- You get "morality points" towards the good ending by exploring (and looting) out of the way spots, listening to incidental conversations all the way through (civilians and enemies both), doing good deeds and avoiding enemy casualties. If you explore well enough, you can skip the pacifist angle and still get the good ending though.
- Don't worry about getting separated from your allies. They will always wait for you to finish exploring, safe and sound.
- Many stealth sections are based around advancing as far as you can without being detected to trigger a conversation that will make the enemies move on to more convenient spots.
- With the exception of "Nightfall", none of the boss fights are about pointing a gun at the bad guy and pulling the trigger for a while. There's always an environmental hazard / vulnerable spot to target.