While I'd never stoop to the old "games cause violence" argument, there's little doubt that games teach us to treat death as a numbers game. Each individual demise isn't important: what matters is the body count, the chain reaction, the comforting tick of small numbers getting bigger.
Pandemic, a morbidly fascinating disease simulator from Dark Realm Studios, is a game that, played successfully, trades in enormous numbers. Get things right and billions of people will die, yet it's always that first death that feels the most exciting and special. It means you're on the right track. The counter will rise.
Pandemic started life as a Flash game on the Newgrounds website that went appropriately viral, but it's been heavily redesigned for its first paid outing as a 69p app. Not all the changes have been for the better, but the ghoulish core of the game has survived intact. If you ever wanted to exterminate mankind, here's your chance.
If you want to get from that first infection to global catastrophe, you need to think about evolution. As your disease spreads you'll earn Evo points, which can be used to add new genetic signatures to your mutating disease. For the most part you'll be adding symptoms, starting with simple things like a runny nose and nausea, building up to horrible stuff like kidney failure and pulmonary embolisms.
You can also unlock various support genes, allowing your disease to survive longer in hot, cold or wet conditions, or to be transmitted by insects, birds or rodents. Pick powerful combinations and you'll also gain access to Traits, essentially the infection vector equivalent of special moves. Evolve a disease strain that leads to crippling fever and encephalitis (or swelling on the brain) and you can add the Head Popper trait, which makes your disease very messy indeed.
There's a balance to be struck though. The more visible and nasty your disease becomes, the harder humanity will work to find a cure. Pandemic's dark heart comes from trying out your own doomsday scenarios; maybe by creating a highly infectious but non-harmful disease that suddenly turns fatal once its spread across the globe. Or you may want to develop something that is both nasty and localised, before making it airborne and watching it sweep the population.
Infection spread is hindered and helped by various factors, particularly the flow of people across borders, and the long term goal is to infect the whole planet - isolated island nations such as the notoriously impregnable Madagascar included - before medicine puts an end to your rule of terror. It's compellingly sadistic, yet educational as well.
Where the app suffers is in a port that concentrates on the gameplay at the expense of presentation, and the rough edges and tiny icons are compounded by a feeble tutorial that will leave most new players confused. The game's timespan is also off-balance, with the slowest speed setting resulting in a game that lasts for hours, while the fastest of the three settings makes everything whizz by so fast you can't actually follow what's happening.
Even with those minor caveats, Pandemic 2.5 is one of the more interesting strategy games on the App Store, and one that dares to make you think about what those numbers actually mean as the body count ticks ever higher.
App of the Day highlights interesting games we're playing on the Android, iPad, iPhone and Windows Phone 7 mobile platforms, including post-release updates. If you want to see a particular app featured, drop us a line or suggest it in the comments.