Normally, when you have a game that's about destroying humanity, you'll be using various epic and violent means of doing so. After all, if movies like Independence Day have taught us anything, it's that humans, by our very nature, are determined to survive or go down in a blaze of glory. Plague Inc, on the other hand, has us go out with a whimper.
This is a game about strategy and subtly. You control and manipulate your custom disease as it spreads across the globe, and as it does, you must be careful to stay in the shadows. While the goal is to kill everyone, being too flashy or effective will result in the population recognizing your precious disease as a legitimate threat, and once that happens, the final portion of the game begins.
During this final portion, mankind and the plague enter into an arms race. One side hurries to create a cure, while you are tasked with finishing off every living human before they succeed. This makes it imperative that you avoid detection until you're ready to pull the proverbial trigger.
All in all, this can be a rather creepy game. However, it's a fun challenge to try and outwit all of humanity. The various types of germs you can use all add twists to the formula, and there are plenty of premade and custom scenarios for you to explore. Who knows; you might even learn some newfound respect for doctors and basic hygiene after you see what effect it has on the simulated world.
While the player doesn't see everything going on behind the scenes, this game's simulation is detailed and complicated enough that it actually managed to gain the attention of the CDC. Obviously, it's not entirely accurate, as it does skew things in order to give the player more of an advantage. For example, transmission from person to person is easier in the game than it is in real life. Another big break from reality is how the diseases evolve: when one germ's traits are changed, all germs in the world change with it. In real life, a mutation only effects one individual and their direct descendants; mutating an entire species at once is completely impossible.
It's not all bleak and horrible
As you play the game, news tickers run continuously. These can display useful information about how your disease is doing, but they can also occasionally display silly messages or reference current real world events. Several of the sillier messages reference other popular games, and more than a few poke fun at the way the game has redrawn the world's countries to make keeping track of things a little easier.
Many types of diseases
Each type of disease has its own challenges. Bacteria are the baseline standard, with no special gameplay quirks, and are thus are well suited for players who are just learning how to play. Once you have the hang of those, you can move on to other germs like viruses, fungi, and parasites. Different infectious agents grow new traits as different speeds, and some start you off with disadvantages. Some examples include the bio-weapon, which is more likely to kill its host than to spread, and the nano-virus, which has a known cure.
When you start exploring the more fantastic diseases, such the necro virus or the simian flu, things get even more bizarre rather quickly. As you might guess, the necro virus turns people into zombies, and the simian flu results in large primates becoming hyper intelligent and bent on world conquest.
Not everyone is a skilled strategist, and so you have the option of four different levels of difficulty. Each level of difficulty has an amusing description that gives you an idea of what to expect. Casual difficulty (the lowest), admits that people don't wash their hands and think it's a good idea to regularly hug sick people. On the flip side, the Brutal difficulty setting forces everybody to wash their hands, doctors work constantly, and sick people are locked away from the general population.
Scenarios alter the way the game is played. This might be done to make things more interesting, to encourage different methods for winning the game, or to provide a new, custom disease using the existing ruleset. There are a number of official scenarios provided with the game, but players can make and distribute their own custom scenarios via the game's online community.
Steam community features
One example of how scenarios can force players to try something new is the artificial organs scenario. A very popular strategy in Plague Inc. is to have your disease lay low until everyone on Earth is infected, and once this happens, you immediately evolve the total organ failure symptom. This method rapidly kills everyone before they have a chance to know what was happening, and thus makes for an easy win. However, in this scenario, people can easily get replacement "parts", making this particular symptom much less effective.
Another official scenario provides an example of a custom disease. In the Board Game scenario, you're not making a deadly plague at all. Instead, you have two years to produce a board game and sell it to everyone on the planet. In place of symptoms and transmission vectors, you have game pieces, product designs, and distribution channels. Since they work as a fill-in-the-blank system, the game's popup messages still say the world is "infected" or refer to your game as a "disease", but otherwise nobody dies this time.
It's easy to fail, even when you're being careful
Like many games on Steam these days, Plague Inc offers a set of Steam trading cards*
that you can earn while you exterminate humanity. But, most of us aren't here for those. Many gamers prefer achievements*
, and there are a LOT of them to collect -- 199 in all as of this review. Most of these achievements*
are earned by discovering specific combinations of symptoms, referred to as "combos". Others are earned by playing the game in certain ways or by completing the official scenarios with high ratings. It'll take some considerable effort to earn them all, so if you think you know your strategy games, then gook luck to you!
This is a strategy game, and you will need some luck regardless of what sort of disease you're trying to manipulate. The two biggest offenders are random mutations and Greenland. The former can expose your germ before you're ready to fight against humanity finding a cure, and Greenland is simply notoriously hard to infect. If Greenland's borders close before your disease makes landfall there, then you've likely already lost.
The goal is to kill everybody
In all seriousness, the end goal of Plague Inc. is to create a "perfect" disease and guide it through the process of infecting and killing every human on the face of the Earth. Thus, every successful playthrough will have a body count in the billions. Fortunately, you don't actually see your victims. Instead, it's all a bunch of charts, graphs, and colored areas on the world map.
However, there are some alternative endings that are also considered a victory for the player. These include enslaving mankind via a mind controlling parasite, turning everyone into something inhuman like vampires, zombies, or neanderthals. It all depends on what disease you're working with.
When working with vampires, zombies, evolved primates, or brainwashed humans, you have the ability to direct their activities like an army general commanding their troops. This allows you to attack various locations or cause destruction in other ways. Still, when it's all said and done, it's presented as icons on a world map. You're told what they are doing, but it's never shown in any detail.