A five-minute demo of Metro: Last Light is enough to showcase scavenging, exploration, and fighting, and to cover ground that includes gloomy, claustrophobic interiors and vast, echoing exteriors where the sky crackles and fizzes with radioactive weather systems. Last Light's the sequel to Metro 2033 - Metro author Dmitry Glukhovsky has been involved, apparently, even if the narrative has nothing to do with his own sequel, Metro 2034 - yet that familiarity provides little comfort in this dirty, post-nuclear wasteland.
The player can seem terribly vulnerable, all alone in this empty world, and mere vulnerability is probably one of the better sensations on offer. After all, the same five-minute demo starts with an uneasy, brooding kind of calm, and ends with all-out frenzy. Five minutes. Let's go.
Our glimpse of Last Light kicks off in the subways, of course: deep within the underground network where the survivors of the nuclear attack on Moscow have fled. It's grim down here - it's grim everywhere - but there are plenty of jarring reminders of the old world, from the empty sarcophagi of the ticket booths, to a jaunty drawing of an ice cream cone on a rust-splattered advertisement.
We're down here searching for supplies, by the looks of it, hunting for the ammo, weaponry, and gas mask filters we'll need for our next mission, which involves heading out of the Metro into the ruined city, and making our way to another station.
Gathering resources remains a huge part of the Metro experience, whether you're picking through drawers and filing cabinets, or plucking filters from unfortunates who don't need them anymore. It's a game where corpses are both a potential treasure trove - what have they got, and what will I find? - and a warning. Who killed them? Are they still nearby?
When we've collected enough bullets to fill up the clip on our side-loading rifle, we're ready to head out - along with our AI ally - and see what things look like up on the surface. Down in the Metro, the world's basically everything you can make out within the weak circle of light from your torch. Up there, it turns out, it's blinding at first, and then your eyes slowly adjust and you're faced with a colossal space to take in - and then navigate.
Moscow's buildings are shattered and starting to scab over with moss and piles of weeds, while the sky above is a boiling muddle of storm clouds. Turns out that letting off a few nukes really screws things up, eh? The dynamic weather system is apparently something you'll always have to keep in mind while moving outdoors, but for now, at least, it seems to be playing along - threatening violence, but delivering little except the odd flash of lightning.
Ahead of us is our target station, but to get there we'll have to cross a downed passenger jet - a jumbo, naturally - that was caught in the shockwave when the bombs hit. We walk across the huge wing of the plane (it now forms a handy ramp) while Stalin's high-rises define the horizon, and condensation spatters the visor of our gas mask.
We pick around rubble, stopping briefly to recharge the lantern on our mask or take in the vivid texturing that brings post-apocalyptic Moscow to life in dozens of nasty little details: the dirty streaks running down the seams in the concrete, the bones poking out of the ground. We're closing in on a sheltered area and another corpse, another gasmask filter. As we grab it, though, spiders, huge and slightly translucent, erupt from the body. Two minutes in, and this is the first glimpse of life. It's scripting, but pretty good scripting, and hopefully a sign of things to come.
Scavenging again - a shotgun, double-barrelled, and a stack of ammo. Turning around, we're lunged at by a ravenous, rabid beast of some kind. Our ally finishes him off quickly, leaving us to wipe the thick red blood from our visor, and then we're on the move once more, ducking outside to see dozens of the things - are they crazed dogs or something more exotic? - rushing past in the distance, moving in packs, paws thundering on the ground.
Now we head for the plane, tugging a hatch on the side and working through the cabin, where grinning, skeletal passengers sit politely, strapped into their seats, and a flashback awaits when we get to the cockpit and see the pilots, fighting for control of the huge vehicle as Moscow disappears in a mushroom cloud and they're swallowed by the flame.
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Talking of flames, we're using a Zippo to burn through thick cobwebbing, and then we're off again, out of the plane and back on the streets. What's next? A bat's next, apparently. Yuck.
It looks like a bat, anyway, a massive, mutated monster who attacks us where the streets start to get narrow, dive-bombing from the sky - briefly picking us up and then dropping us - and making the most of the fact that it's beginning to get dark. The bat zips in and out through the weak light from our torch, making it hard to get a bead on him, and in a game about making every bullet count, a game where some bullets, remember, serve as currency, he's encouraging us to waste ammo in wild bursts.
There's still no HUD, but the state of our breathing is suggesting that we should probably just run, eh? Into a nearby theatre - that Metro we're after must be nearby somewhere - and then down, fighting a sudden influx of mutated dogs as we go. Escalators beckon, and then we're waiting for the Metro barricades to open, burning our last precious clips on the monsters pursuing us until new allies emerge, with hazmat suits and flamethrowers, torching everything in sight.
Finally, we're inside, and the doors start to close. No ammo left. No filters left. Five minutes. Done.