Trains appearing in video games.

There are several reasons why I'm looking forward to Metro Exodus.

The Metro series is dripping with tension, atmosphere and character. The games have great pacing and combine claustrophobic chills with dangerous open spaces, and fast-paced gameplay mixed with bizarre supernatural elements. They're also not afraid to touch on real world themes and let us bludgeon fascists.

Exodus pushes the series forward by taking the adventure from the tunnels to the world. You'll explore these new lands, traversing uncharted territory aboard the Aurora, a heavily modified steam locomotive. That's a good thing, because it's a proven fact that trains make the game better. This is science.

I'm 100% serious about it. What are your favorite moments from the Uncharted series? I bet at least one of them involves a train. Half-Life 2 is an all-time classic, and the game starts on a damn train - it's the opening sequence that establishes the world by showing it in short shots. This sequence became the standard opening shot for other first-person shooters for a while. Even Red Dead Redemption found it to be an appropriate way to start the game.

Gears of War reversed the train-based intro and used it as an exciting way to end the game. It was botched a bit with a terrible final boss, but the intro was good. Why it was good. The Train.

Trains play an even bigger role in Red Dead Redemption 2. There are several missions built around locomotives - including one of the first - where you have to chase them down, stop them, or fight with wagons as they speed through open spaces. Locomotives also play a big part in the open world itself, providing an element that you can hijack and stop. You can even drive these things and pull the whistle. Choo, choo, motherfucker.

So, what is it about trains that give them this power to elevate a video game? For one thing, trains sort of drive themselves and follow a predetermined route, which fits our medium perfectly (and is also a metaphor for some video games). They also act as a moving level.

The level design itself - in its most basic form - can be a straight line, but the changing environment can add dynamism to the scenery. One minute you might be circling a snowy mountainside, and then, suddenly, you're going through a dark tunnel and popping out on the other side onto a green plain.

There are also a few ways to spice up this level design. There's a passage in the train car, but the seats serve as cover, allowing you to push forward. If your game offers melee combat, you can also take advantage of environmental subversion by drowning enemies in toilets, smashing their heads into poles, or toppling a tray of seats right into their face. The rooftop, meanwhile, is another optional route that comes with some dangers and benefits. There's the risk of falling, as well as being hit by low-hanging signs and tunnel entrances. Perhaps these environmental hazards will force players to hang off the sides of the wagon, adding another tactical grind.

One of the best games that captures the versatility of the speedy metal tube is Splinter Cell: Pandora Tomorrow. The player is tasked with infiltrating a moving train. Light and shadow force you to think about your next move, sometimes telling you to slide over the side of a train car or dangle from pipes underneath, inches from the tracks to avoid detection. A real sense of speed makes this suitably terrifying.

You creep through freight rooms and past civilian train cars, avoiding onlookers lazily peering out the window, using cues such as yawning to make your move. The large civilian presence cleverly forces you to make tentative progress.

I can't recall a single instance where a train in a video game detracted from the gaming experience. Even the mod for Skyrim Thomas the Tank Engine is a testament to this universal principle. So let's put more trains in games. Let's see what else we can do with this concept beyond what's already established. The mobile base of Metro Exodus sounds like a good start, but there's so much potential to be tapped, especially in multiplayer games where static arenas still reign supreme.