There is little symmetry, too, which further complicates matters. One side of the map is on higher ground and provides a proper vantage point, but the low ground is peppered with vastly superior cover. It means you have to noticeably adjust your tactics depending on where you are, and with a greater extent than most other maps. If you're smart, you'll stick with an assault rifle.
Unlike Call of Duty 4's Countdown - also set in a missile silo - this map seems to be set in a converted quarry, littered with haphazard cement tubes and an abundance of tarpaulin. Missiles constantly launch in the background while the action is playing out, which adds a nice touch to an otherwise standard looking map.
I find Silo fascinating but not exactly entertaining - it's too big, for a start, and the central areas are basically locked off unless you want to be immediately shot in the head. The end result is a map where you essentially run around the edges while trying to make sure you're not getting chased from behind. That's not exactly thrilling. I'm sure it will prove difficult for the many players who stick to their tried-and-tested techniques, too - one polite fellow in a game over Xbox LIVE described Silo as an "absolute clusterf**k" and then said something I would not be allowed to repeat. Delightful.
On the opposite end of the scale we have Drive In, which fancies itself as the next Nuketown. It certainly lacks Nuketown's simplicity, however, packing together dense combat zones and flanking opportunities within the aesthetic wrapper of the iconic American drive-in theatre.
The golden area is the cinema screen itself, which gives you a wide reaching view of the car park and the periphery areas. It's an obvious magnet for snipers, but hard to secure because there are more entrances than there are claymore mines. Not much about Drive In is particularly flash or inventive, but its design produces some decent close-quarter skirmishes.
Drive In exists to satiate the need for a small map. It's one of the few maps in Annihilation that feels like it isn't made with the Ground War playlist in mind, and I've had a few intense Search & Destroy matches within its confines. The big problem is that it seems to inspire a few too many players to equip Ghost and hide around corners, but it's packed with just enough areas to be interesting, and it certainly isn't on the same level as Nuketown when it comes to rampaging manshoots.
Rounding out the competitive maps is Hangar 18, which chucks everyone into a slice of Area 51. There's (presumably) zombies, a few aliens, and in one corner there's a levitating apple in some kind of antigravity tube, which even makes funny noises when you shoot it. And you will try and shoot it.