Despite being a sequel to Metro 2033, Metro: Last Light is a lot like an original title.

So says THQ's communcations manager, Jeremy Greiner, anyway. Unlike Metro 2033, Metro: Last Light has had a real marketing push - this time publisher THQ is all in. The company has gone so far as to give away PC copies of Metro 2033 completely for free when consumers 'like' a Facebook page, and the game's inclusion in the recent smash-hit Humble THQ Bundle can't have hurt the old-but-new title, either.

"Pretty much every game that's releasing out there has a two next to it, or a three, or is a rebrand," says Greiner, speaking to PC World over the phone during a recent trip to Sydney.

"This is a great experience for those that want to have something new, wanna try something new when most games coming out right now are sequels."

Metro: Last Light is a survival/horror first-person shooter set in a post-apocalyptic world, which will surprise no one. But the setting is different to the usual swarm of zombies on a grey-brown landscape, which Greiner says is down to the developer's specific view of the world.

"The typical post-apocalyptic world from the Western studios is all pretty much the same, but the bleak Russian vision is certainly unique," he says.

Instead, Last Light is set after the nuclear holocaust. Humans have been driven underground, while violent mutant creatures called the Dark Ones populate the surface.

What makes Metro: Last Light different from other first-person shooters out there? The most noticable thing will be the lack of any obvious UI elements. There's no mini-map telling you where to go, no words popping up on the screen every five seconds. In 2033, elements were pretty bare, but in Last Light everything has been stripped away. Those elements are instead worked into the game. You wear a gas mask with a limited amount of oxygen, for example, and have to keep an eye on your watch to know when you're going to run out of air.

"What we're hoping to do is make a truly immersive, atmospheric FPS experience. And in order to do that stripping away all those [heads-up display] elements just makes you more immersed in the world," says Greiner.

"So you're looking at the people talking around you, or you're looking at the child's drawing on the floor, or you're looking at, you know, the artwork on the wall or the shadow that pops in the corner."

Unlike Metro 2033, Last Light is entirely the baby of developer 4A Games. 2033 was based on a novel of the same name by Russian author Dmitry Glukhovsky, but with its sequel 4A chose to move away from the book's sequel, Metro 2034. You still play as the main character from the first game, Artyom.

It's also designed to be terrifying. Some games build you up with bravado, but Last Light means to break you down with fear. Most of the game takes place in the dank, dark tunnels of the Metro under Moscow.

"You go up to the surface a few times -- it's a nice break from the dark tunnels in the Metro -- but it's part of the key pacing of the game," says Greiner.

Gameplay can't always be "at 11", so the game also takes the time to show you how the nuclear holocaust has affected characters on a very personal basis.

"A lot of the game is about creating emotion," Greiner says. "A lot of what the game does, especially for a core shooter fan, is over the course of time as you play through it it challenges your preconceptions and your normal habits in a shooter."

The game challenges your thinking not just through emotional impact, but because of the little, almost invisible decisions you make when playing. Metro 2033 had two endings - a "good" ending and a "bad" ending, but the decisions you made to get there were much less obvious than in most games. The "bad" ending has been taken as canon, however, for the purposes of the sequel.

4A Games has gone the same route with Last Light. There are thousands of small choices that add up and can change the outcome of the game. Choose not to kill an enemy who's begging for his life? That choice will change what happens to Artyom.

"What's typical in most games out there is it's usually a conversation tree and it usually has yes or no answers or good and bad answers or right and wrong answers, or actions that you can do. And when you're presented with something in that manner you don't choose based on how you'd normally play the game. You choose based on what outcome you want, right?" says Greiner.

"So the fact that they were able to successfully pull off [that mechanic] in Metro 2033 meant they'd definitely be using it again in Last Light."

Metro: Last Light is set for release in March 2013.