Metro 2033 is where the bulk of the remastering went. It looks almost as if it were built from the ground up using the updated 4A Engine similar to that of Metro Last Light, but a more realistic idea is that the textures and placements of some objects were given a fresh coat of paint that still looks absolutely fantastic. Unfortunately though, the best comparison image I could find was a compressed YouTube image that doesn't do it as much justice as I would have hoped it would, but I think it still gets the point across.
As well as a graphical upgrade, Metro 2033, also gets an upgrade to it's HUD and menus. Now it's exactly like Metro Last Light where you hold down a button or key that brings up all your tools. This is a million times more convenient than the older Metro 2033 HUD and menus though I can see why some people may not like it feeling like the same game, but i like it being two different games feeling like one huge video game ride.
Some times you will be given a small side quest for money or a karma point towards the good or bad though it doesn't really matter because Last Light will always pick up after the bad ending. I can not say enough good things about this game. It's really more like an experience because even after you've finished the game you will never forget the experience you had with it. Since you can buy each game separately I give this game on it's own merit a 9/10.
Metro Last Light picks up right after the bad karma ending to 2033 where Artyom launched the missle strike against the Dark Ones' nest, but only after it's revealed to him that the Dark Ones were actually good and mean't no harm to humans and actually wanted to help them rebuild humanity. Khan, from 2033, visits Artyom and reveals to him that one Dark One survived so now it is race to get the last remaining Dark One. You will fight against the Fourth Reich, the Soviets, and bandits as well as everybody's favorite mutated dog things; Nosalises.
Artyom also gets a love interest named Anna whom the developers spent more time modeling her boobs than her face (you'll see what I mean in a minute). Anna actually goes through a bit of a character arch. She starts out as a real bitch to Artyom then through a set of events she respects and becomes attracted to him. Anna isn't given a lot of screen time though. She's at the beginning of the game then disappears for more than half the game to show up towards the end. Artyom still only speaks during loading screens and remains silent during gameplay which makes me wonder how he ever gets Anna.
This is what I meant when I said that the developers spent more time modeling Anna's boobs than her face. I have to note that the breasts and nipples are the most realistic I've ever seen in a video game (which is warrant enough for a 10/10 amiright, guys??) The nudity is kind of strange in this game though. Both times it happens you are in a really intense fire fight then less than 5 minutes later you get boobs in your face. I'm not really complaining for that reason, but it did hurt some of the pacing for two really intense parts.
The first time you on a raft with another survivor fighting off mutated water monsters called "Shrimps" to get to a nearby station then you get a bare breasted lap dance. It is optional though. The second time you shooting your way through a metro station that is burning down and are trying to get to Anna because she was captured by the Soviets in the last mission. At the last moment the enemy breaks you gas mask and you are exposed to a biological weapon that the Soviets tested on the metro station with. You and Anna are then both saved and quarantined by Khan and his men because the biological weapon was Ebola. In the face of uncertain death Anna gets partially naked and Artyom and Anna make a baby.
There are less side quests to do in most of the stations though. You'll still see your typical bum in the corner asking for a bullet and you can still give him one for a good karma point. Metro Last Light also has the ability to get a good ending and a bad ending except this time one of the endings implies a sequel to this game and the other ends the series. You'll see which is which depending on the ending you get. 9/10.
So, I'll stop gushing for a moment and get down to it. Metro Redux isn't flawless. Stealth is some times way too easy. There are some minor animation hiccups here and there. Last Light has minor pacing issues, but overall these games are amazing. The story is well told, the atmosphere is incredible, the gameplay is rock solid, boobs, and you get to kill Nazis. What more could you possibly want. Both Metro 2033 and Last Light have both been remastered and it shows (more in 2033). You also get both games for the price of one. I highly recommend you pick this one up on any platform of your choosing. I know that it should average out to about a 9/10, but I'm taking into account you get two games for the price of one. Overall I give Metro Redux a 9.5/10. It's that good.