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Short feedback and suggestions for more realistic mechanics
30-07-2014, 07:36 PM (This post was last modified: 30-07-2014 07:39 PM by TheAnnoyingGunner.)
Post: #1
Short feedback and suggestions for more realistic mechanics
Hi everyone! After playing Plague Inc: Evolved "through" (which means having played every pathogen type in at least a couple of matches), I thought I give some feedback here, where maybe the developer stumbles over it and might find inspiration in some ideas. Suggestions are not all that fancy, I try to stay realistic as the game itself mostly tries to hold onto realism (to some degree). So beware of some short (molecular) biology excourses.

So first of all: I love the idea of the "have virus go kill them all" and so far I had a good time with the game in it's current state. But there is still some way to go, I think there is a number of opportunities where the gameplay could be improved.


1. User Interface
As I am quite new to the game, I think I can give some short input on user friendliness. This far, I never used the chart once, as it didn't seem of any use for me.
Often the spreading of the infection in a country stops or is simply carried too slowly
because the government took precautions. To compensate this, I have to evolve my pathogens transmission vectors, but evaluating the best option is tiring as the governments countermeasures are a long list of text where you have to search for specific entries. Why not include symbols for this like they are already shown for borders, airports and harbours, if some transmission type is inhibited?
Then, sometimes the whole world is totally infected but a little country in the middle of nowhere. Maybe I missed something, but the game only tells me with the bottom bar that there are some people still healthy. The only way to find the country with the !partially! infected population is by clicking through them all. Maybe add a heat map overlay to show where your pathogen is dominant or lacking?


2. More diversity with the symptoms
I was rather annoyed by the fact, that most of the classic pathogens play mostly the same. The only difference is the specific ability and in case of the fungus that it spreads very hesitantly. I enjoyed playing the Necroa virus and the Neurax worm as they introduced new features that completely change gameplay.
What I am missing is for example a pathogen related symptomatic evolution tree as it is featured with the Neurax or the newly introduced Simian Flu. At the moment, the pathogens are highly similar, the transmission, symptoms and ability core tree are identical.
Especially the symptoms tree should be customized for the different pathogens.
Some examples for two pathogens, based on realistic pathogenesis:
Fungus
Fungi are eukaryotes, they infect tissue via sporulation and grow inside the surface layer of the body, the epidermis and mucosa. Therefore, the initial symptoms are confined to the upper part of the symptoms tree. Later on, with further growth of the mycel or through evolution, side effects can be chosen. These side effects are mostly the stuff of the lower half of the symptoms tree, excluding cysts. Fungi utilize spores for infection, using different kind of sporulations (launched sporangium greatly enhances infectivity but severity, konidium sporulation has lower infectivity but therefore almost no severity).
Prion
The prion is a more sophisticated pathogen. It is a misfolded and very stable protein and therefore should be treated completely different than the other pathogens. Reality looks like this: Transmission through ingestion, disinfection is nearly impossible. It takes a very long time to evolve in it's host. The prion induces misfolding of proteins which become prions themselves. They cannot be digested by cell internal proteases (protein cutting enzymes) and accumulate, building up large clumps which finally lead to the cells death due to disruption or other means not fully understand. This is most detrimental to the slow replicating neural cells (the brain), all prions primarily affect brain tissue, causing spongiform encephalopathy (most prominent BSE).
Admittedly, removing everything but brain damage from the symptoms tree would be lame, but at least it should be the anchor point for this pathogen with deadly symptoms from the very beginning. The "feature" of the prion is it's long incubation time and slow transmission, the pathogen can be spreaded relatively far before it is noticed. Real world prions cannot be cured (or at least nobody has found out so far), applying this to the game could mean that the research wouldn't develop a cure but a detection method, where infected population is being separated completely from the healthy population to avoid further infection. This hasn't to be the end, but the player should keep some doors open to develop new transmission types that undermine the quarantine and infect quicker than the infected can be excluded from society. Or the already infected die due to the disease or military strikes. Not 100% correct, but amusing for sure. Humanity wouldn't find a sudden death, but would slowly pine away.


3. More diversity with the transmission
Here too, most pathogens are the same. Suggestions:
Bacterium
Compared to the virus, the bacterium has the big advantage that it is a living organism. It doesn't have to be in it's primary host to replicate, it can do so while being out in the wild. This heavily increases infectivity. The formation of endospores (the bacterium dehydrates itself into a "spore" to resist harsh exposure over long time, not to be confused with the cell wall) can hugely increase the infectivity and infectious half time of the pathogen (for the last one, look at the suggested new mechanic further below).
Virus
The virus is no organism (=living), therefore it is very resilient against most kinds of treatments, depending on the virus type (the more complex, the easier to get rid of, at least prior infection). A virus is a very small particle, therefore highly transmittable via dust particles, compared to other pathogens. The efficiency of a virus differs with it's delivery form, the simplest method is a simple virion, but the player could increase it's complexity - develop the virion coated by an envelop (it is coated in the hosts cell membranes, this vastly negates host immune response, increasing efficiency).
As I don't want to do the same thing again for abilities: At the final step of the virus instability, your virus could become a retro virus, with all it's benefits and drawbacks. The retrovirus is highly instable which causes random dynamic mutations in both directions - the addition of symptoms as well as the removal. Mutations would occur at random intervals with multiple mutations at once. If base oxidation or hydrolisation is activated, this can be detrimental due to reverse mutation obstructing certain transmission pathways or removing resistances.
This also strongly impedes cure research (setting the cure back a few percentage points with every mutation event) and would increase the symptoms effectivity. The switch to Retrovirus cannot be undone, so the player has to live with his decision.
Fungus
Fungi can grow on different substrates, therefore a greater flexibility could be added to the transmission tree. Additional habitats of the fungus could increase infectivity and form new combos. If the fungus is able to form lichens, it could grow on buildings and generally in wet areas, together with the air transmission it would form a transmission combo, increasing the air transmissions effectivity in non arid environments (let's just pretent lichens grow a little bit faster than they really do). The governments would not have the means for countermeasures, so this is a slow but dead certain way to compromise stubborn countries). On the other hand, the fungus could be advanced to grow saprophytic (on corpses), which would form a wonderful combo with avian transmission, especially effective in rural and poor areas and increasing the impact of avian transmission (which means if birds are disposed and you don't have the upgrade for wildlife, you're outsmarted). Therefore it could be a whether - or decision, long-term/slow or risky/fast.
Parasite
Parasites are mostly transmitted through direct contact with the parasite or it's eggs. As the eggs of eukaryonts can be easily eliminated via ultrafiltration, the water transmission is a very unlikely way in wealthy regions (if you don't pull your water out of your gardens well, it has undergone ultrafiltration). Naturally the parasite would have a low infection rate in wealthy regions, but a very high infection rate in poor regions.


4. New Mechanic: Pathogen elimination in host
This is a more advanced mechanic. At the moment, if a person is being infected, it will stay infected until he or she meets their gruesome death. This is a very simple mechanic and changing this to a more realistic model (optional or on a higher difficulty) would do the game much good in my opinion. Atm, you could simply sit out the infection of the whole world with a ninja pathogen that shows no symptoms and then build up deadly symptoms, genetically synching every single pathogen over the whole globe in an instant (virus, bio-weapon). Well, tracking genetic diversity would be a bit much to ask, but the infection model could be improved. Most pathogens get eliminated from the host after the immune system has adapted, which takes about 2-3 weeks for a immune response. After this, you have a time of different length where the immune system is attuned to this specific pathogen (especially with viruses and bacteria) and a reinfection is unlikely. The post-infectious immune phase is most probably not calculable on a global scale, but at least the population with an acute infection could decrease. Means, if you don't spread in a timely manner, you die out, no cure needed. This would be especially true if a country has a minimal amount of infected persons, closed borders and appropriate precautions to keep the disease from spreading further. This might result in a quarantined country full of healthy people that are hard to tackle. Different pathogens could offer different traits for the transmission and infectious half time.
Fungi would spread very slowly but could offer constant exposure to spores, which keeps local population infected (as mentioned unter point 3) and the governments have no effective countermeasures for some transmissions available.
Viruses are easily transmitted via dust particles in the air and therefore people of a great area are exposed to the particles additionally to the smear infection, but resistance builds up relatively fast.
Bacteria are versatile and balanced, their trait is a high initial infection probability and increasing infectious half time with increasing cell wall.
Prions spread slowly and especially through cattle and water, but in exchange don't build up resistances, the host stays infected.
Parasites mostly avoid the hosts immune response, but are more constricted in the transmission types (ideal for the start in poor regions).


I hope you guys find a liking in my ideas and it was not too dull too read (excourses...).
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31-07-2014, 10:11 AM
Post: #2
RE: Short feedback and suggestions for more realistic mechanics
(30-07-2014 07:36 PM)TheAnnoyingGunner Wrote:  Hi everyone! After playing Plague Inc: Evolved "through" (which means having played every pathogen type in at least a couple of matches), I thought I give some feedback here, where maybe the developer stumbles over it and might find inspiration in some ideas. Suggestions are not all that fancy, I try to stay realistic as the game itself mostly tries to hold onto realism (to some degree). So beware of some short (molecular) biology excourses.

So first of all: I love the idea of the "have virus go kill them all" and so far I had a good time with the game in it's current state. But there is still some way to go, I think there is a number of opportunities where the gameplay could be improved.


1. User Interface
As I am quite new to the game, I think I can give some short input on user friendliness. This far, I never used the chart once, as it didn't seem of any use for me.
Often the spreading of the infection in a country stops or is simply carried too slowly
because the government took precautions. To compensate this, I have to evolve my pathogens transmission vectors, but evaluating the best option is tiring as the governments countermeasures are a long list of text where you have to search for specific entries. Why not include symbols for this like they are already shown for borders, airports and harbours, if some transmission type is inhibited?
Then, sometimes the whole world is totally infected but a little country in the middle of nowhere. Maybe I missed something, but the game only tells me with the bottom bar that there are some people still healthy. The only way to find the country with the !partially! infected population is by clicking through them all. Maybe add a heat map overlay to show where your pathogen is dominant or lacking?


2. More diversity with the symptoms
I was rather annoyed by the fact, that most of the classic pathogens play mostly the same. The only difference is the specific ability and in case of the fungus that it spreads very hesitantly. I enjoyed playing the Necroa virus and the Neurax worm as they introduced new features that completely change gameplay.
What I am missing is for example a pathogen related symptomatic evolution tree as it is featured with the Neurax or the newly introduced Simian Flu. At the moment, the pathogens are highly similar, the transmission, symptoms and ability core tree are identical.
Especially the symptoms tree should be customized for the different pathogens.
Some examples for two pathogens, based on realistic pathogenesis:
Fungus
Fungi are eukaryotes, they infect tissue via sporulation and grow inside the surface layer of the body, the epidermis and mucosa. Therefore, the initial symptoms are confined to the upper part of the symptoms tree. Later on, with further growth of the mycel or through evolution, side effects can be chosen. These side effects are mostly the stuff of the lower half of the symptoms tree, excluding cysts. Fungi utilize spores for infection, using different kind of sporulations (launched sporangium greatly enhances infectivity but severity, konidium sporulation has lower infectivity but therefore almost no severity).
Prion
The prion is a more sophisticated pathogen. It is a misfolded and very stable protein and therefore should be treated completely different than the other pathogens. Reality looks like this: Transmission through ingestion, disinfection is nearly impossible. It takes a very long time to evolve in it's host. The prion induces misfolding of proteins which become prions themselves. They cannot be digested by cell internal proteases (protein cutting enzymes) and accumulate, building up large clumps which finally lead to the cells death due to disruption or other means not fully understand. This is most detrimental to the slow replicating neural cells (the brain), all prions primarily affect brain tissue, causing spongiform encephalopathy (most prominent BSE).
Admittedly, removing everything but brain damage from the symptoms tree would be lame, but at least it should be the anchor point for this pathogen with deadly symptoms from the very beginning. The "feature" of the prion is it's long incubation time and slow transmission, the pathogen can be spreaded relatively far before it is noticed. Real world prions cannot be cured (or at least nobody has found out so far), applying this to the game could mean that the research wouldn't develop a cure but a detection method, where infected population is being separated completely from the healthy population to avoid further infection. This hasn't to be the end, but the player should keep some doors open to develop new transmission types that undermine the quarantine and infect quicker than the infected can be excluded from society. Or the already infected die due to the disease or military strikes. Not 100% correct, but amusing for sure. Humanity wouldn't find a sudden death, but would slowly pine away.


3. More diversity with the transmission
Here too, most pathogens are the same. Suggestions:
Bacterium
Compared to the virus, the bacterium has the big advantage that it is a living organism. It doesn't have to be in it's primary host to replicate, it can do so while being out in the wild. This heavily increases infectivity. The formation of endospores (the bacterium dehydrates itself into a "spore" to resist harsh exposure over long time, not to be confused with the cell wall) can hugely increase the infectivity and infectious half time of the pathogen (for the last one, look at the suggested new mechanic further below).
Virus
The virus is no organism (=living), therefore it is very resilient against most kinds of treatments, depending on the virus type (the more complex, the easier to get rid of, at least prior infection). A virus is a very small particle, therefore highly transmittable via dust particles, compared to other pathogens. The efficiency of a virus differs with it's delivery form, the simplest method is a simple virion, but the player could increase it's complexity - develop the virion coated by an envelop (it is coated in the hosts cell membranes, this vastly negates host immune response, increasing efficiency).
As I don't want to do the same thing again for abilities: At the final step of the virus instability, your virus could become a retro virus, with all it's benefits and drawbacks. The retrovirus is highly instable which causes random dynamic mutations in both directions - the addition of symptoms as well as the removal. Mutations would occur at random intervals with multiple mutations at once. If base oxidation or hydrolisation is activated, this can be detrimental due to reverse mutation obstructing certain transmission pathways or removing resistances.
This also strongly impedes cure research (setting the cure back a few percentage points with every mutation event) and would increase the symptoms effectivity. The switch to Retrovirus cannot be undone, so the player has to live with his decision.
Fungus
Fungi can grow on different substrates, therefore a greater flexibility could be added to the transmission tree. Additional habitats of the fungus could increase infectivity and form new combos. If the fungus is able to form lichens, it could grow on buildings and generally in wet areas, together with the air transmission it would form a transmission combo, increasing the air transmissions effectivity in non arid environments (let's just pretent lichens grow a little bit faster than they really do). The governments would not have the means for countermeasures, so this is a slow but dead certain way to compromise stubborn countries). On the other hand, the fungus could be advanced to grow saprophytic (on corpses), which would form a wonderful combo with avian transmission, especially effective in rural and poor areas and increasing the impact of avian transmission (which means if birds are disposed and you don't have the upgrade for wildlife, you're outsmarted). Therefore it could be a whether - or decision, long-term/slow or risky/fast.
Parasite
Parasites are mostly transmitted through direct contact with the parasite or it's eggs. As the eggs of eukaryonts can be easily eliminated via ultrafiltration, the water transmission is a very unlikely way in wealthy regions (if you don't pull your water out of your gardens well, it has undergone ultrafiltration). Naturally the parasite would have a low infection rate in wealthy regions, but a very high infection rate in poor regions.


4. New Mechanic: Pathogen elimination in host
This is a more advanced mechanic. At the moment, if a person is being infected, it will stay infected until he or she meets their gruesome death. This is a very simple mechanic and changing this to a more realistic model (optional or on a higher difficulty) would do the game much good in my opinion. Atm, you could simply sit out the infection of the whole world with a ninja pathogen that shows no symptoms and then build up deadly symptoms, genetically synching every single pathogen over the whole globe in an instant (virus, bio-weapon). Well, tracking genetic diversity would be a bit much to ask, but the infection model could be improved. Most pathogens get eliminated from the host after the immune system has adapted, which takes about 2-3 weeks for a immune response. After this, you have a time of different length where the immune system is attuned to this specific pathogen (especially with viruses and bacteria) and a reinfection is unlikely. The post-infectious immune phase is most probably not calculable on a global scale, but at least the population with an acute infection could decrease. Means, if you don't spread in a timely manner, you die out, no cure needed. This would be especially true if a country has a minimal amount of infected persons, closed borders and appropriate precautions to keep the disease from spreading further. This might result in a quarantined country full of healthy people that are hard to tackle. Different pathogens could offer different traits for the transmission and infectious half time.
Fungi would spread very slowly but could offer constant exposure to spores, which keeps local population infected (as mentioned unter point 3) and the governments have no effective countermeasures for some transmissions available.
Viruses are easily transmitted via dust particles in the air and therefore people of a great area are exposed to the particles additionally to the smear infection, but resistance builds up relatively fast.
Bacteria are versatile and balanced, their trait is a high initial infection probability and increasing infectious half time with increasing cell wall.
Prions spread slowly and especially through cattle and water, but in exchange don't build up resistances, the host stays infected.
Parasites mostly avoid the hosts immune response, but are more constricted in the transmission types (ideal for the start in poor regions).


I hope you guys find a liking in my ideas and it was not too dull too read (excourses...).

Thanks a lot for sharing - and welcome to the forum Smile

Really like the way you've gone into a lot more depth scientifically on the different disease types. We've always tried to balance some degree of scientific accuracy with the gameplay being fun and easy to understand - perhaps in future it might be cool for us to do a more hardcore scientific mode...
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31-07-2014, 01:25 PM
Post: #3
RE: Short feedback and suggestions for more realistic mechanics
Well, I am no biologist but a molecular biologist (DNA, proteins and stuff), so the biol. aspects of the pathogens are probably not 100% correct (for a "hardcore scientific" mode). I tried to keep them in a way so it would overall work with the game, mostly realistic pathogen behaviour would make the prion useless as it is either transmitted via food (you see what happened with BSE, not much - and in the future prions will have even lesser impact) or through heritation (Creutzfeldt-Jakob) which would take AGES, it's a totally other scale and you would have to watch a scope of... don't know, maybe a few thousand years?
Meh. I prefer unrealistic over boring Wink
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