At first glance it might seem easy to group Metro 2033 under the broad banner of grimy generic modern shooters. Post-nuclear setting, lots of gray and brown industrial environments, two weapons at a time and lots of Russian dudes being killed. But there are a few things that set it apart, like a greater focus on stealth and world building; the fact that every character is Russian (including the non-pricks) and the rather intriguing idea that bullets are used as currency.

In fact, the first time I heard about Metro 2033 was when someone said "Hey, have you heard of this new shooter that's coming out? It uses ammo as currency." It's a concept that easily stands out, and which makes a lot of sense when you think about it. Of course a society based almost entirely around survival on a knife-edge would have an economy based on things that allow you to defend yourself. In our, nice, safe society, it's the person with the most money we all want to be friends with, but the good times will end very quickly if a giant nuclear rat might jump out at any moment and chew his lungs out.

I do think, however, that the Metro series cops out of the idea on two fronts: firstly, it's only "special" ammo rounds that can be used as currency, while standard "dirty" rounds are only good for firing. And secondly, there isn't much you can actually spend the "money" on, except more dirty ammo or weapon upgrades in a pinch.

What that takes away from the concept is the notion of bullets being absolutely central to life, not just survival. It'd be interesting if the same concept were put in a situation where you could spend the bullets on other things that have a gameplay effect. Like if there was a survival mechanic that hinged on regularly eating food, so you had to sacrifice a little bit of your self-defense capability just to survive day to day. Every time you fired off a burst of rounds while in the field, you'd be haunted by visions of the many grilled cheese sandwiches that are now denied to you.

I suppose the bullets-as-money thing appeals to me because I like to see some outside the box thinking, especially when it comes to streamlining the essential processes of a videogame. In a lot of games, you might be able to sell bullets in a shop, and then use the money to buy something else, but see how Metro 2033 cunningly cut out the middle man there.

The thing about gameplay is that it's all about numbers, and every decision the player makes is essentially an exchange of one number for another. Sometimes that's obvious, like when they use in-game currency to buy a better weapon or armor, that's taking a hit to the money number in return for an increase in the attack or defense number. But it applies to simpler gameplay models, too. Even if you're playing a shooter and all you have is one number for health and one number for ammo, the main purpose of ammo is to be exchanged for continued life. And health is exchanged for ammo when, say, you have to run out into the open to recover pickups.