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Game Description
 
The Manhattan Strain is a game demo I developed as part of the Irish team for Dare to be Digital in 2008. The game is about a deadly virus outbreak on the island of Manhattan. The virus is extremely contagious, spreads very quickly and can kill in hours. The threat of a national epidemic has become very real and FEMA (the Federal Emergency Management Agency) have been called in to deal with the crisis. The player takes control of the head of FEMA and has to use all resources at his disposal to contain the spread of the virus.
 
The Manhattan Strain is an RTS built for the PC using C# and the Microsoft XNA framework. It was built over a 10 week period (9 weeks for us as we had to start late) with a viciously strict deadline and had to be presented to the public during the Edinburgh Interactive Festival in August 2008.
 
I was tasked with the gameplay and mechanics programming of the game. I programmed the camera, keyboard and mouse input, unit selection and orders, placing and controling roadblocks, collsion detection, context sensitive controls, the minimap, gameplay logic, text input and message system, a couple of small HUD interface elements and some of the underlying engine code for object representations.
 
The official website set up for the game can be found here
 
 
 
 
 
 
You can download the game from this link (100 mb):
 
If the above link doesn't work it can also be downloaded from this link:
 




  
 
 
 
Getting the game working is a little tricky. This is mainly due to some retrospectively bad design decisions that occured during the development process.
 
First of all the game requires a full installation of visual C# 2005 with the sp1 upgrade, XNA 2.0 and the .net 2.0 framework.
We ended up using an XNA service at one point in the development that only exists in the full installation, unfortunately it won't work with the XNA redistributeable.
The annoying thing is that the final version of the game doesn't even use the the service but it still won't run without the full installation.
 
To get the game to  run correctly and at a full screen resolution, you have to manually change the resolution of your monitor to 1024 * 768 The game will then run at the full resolution of the screen. The reasoning for having to do this is that we used windows forms for the pop up interface in the game. it seemed like a good idea at the time and would save us effort with images. It turned out though that when the application was full screened the forms couldn't be brought to the foreground. We had to cheat a bit to make it work.
 
When you have all that done just run the .exe file in the The Manhattan Strain folder and it should work.
 
 If you are having any issues with it please contact me and I will attempt to sort them out for you.
 
 
Visual C# express 2005 iso:
 
 
Visual C# express sp1:
 
 
 
 
XNA 2.0:
 
 
 
 
 
 
There are some instruction images included in the zip that show the basic controls but there some areas that aren't explained in enough detail and there are some tricks to actually using some of the features in the game. I'm going to attempt to give a more precise set of instructions and steps needed to play the game.
 
Adding and Removing Roadblocks:
 
Placing a roadblock can't be done by simply clicking on a position and having the roadblock just appear at that location. This is because you the position clicked might be over a building and obviously a roadblock can't be placed in a building. To use them properly you must first click on the place roadblock icon, when the cursor changes to have a little roadblock symbol on it you can then place the roadblock. To actually place the roadblock you must hold down the left button on your mouse and drag the cursor across the map. As you are draging the cursor you will see a preview of the roadblock appearing in the level. This will let you see see where the roadblock will appear when you let go of the left button If you try to drag it into the middle of a building or park you will notice that the roadblock does not appear. When you are satisfied with the position of the roadblock let go of the left button and the roadblock will be added to the level at that position.
 
You are only able to place a limited number of roadblocks so if you have reached the limit and want to add a new one, you must first remove a roadblock that is currently active. To do this you simply have to click on the roadblock you want to remove and in the pop up window click on remove button. This will remove the roadblock from play and free up all cops and biologists assigned to it.

  
                                                                          

 Selecting Units
 
There are 4 ways to select units in the game.
 
First, You can simply click on any single unit to select it. Selecting a unit in this way will create a pop up that will give you information on that person. This is the only way to select civilians in the game.
 
Second, You can hold down the left mouse button and drag across the screen to create a selection box which will select all cops and biologists within it's borders.
 
Third, You can use the HUD interface to select unassigned units. By clicking on the green boxes seen in the image below you can select the relevant unit. The number inside the box states how many unassigned units are available for selection. Each click selects one unit and you can select both cops and biologists at the same time to give them orders.
 
 
 
 
 
 
The final method of unit selection is a context based one. If you have units assigned to a roadblock or building and you wish to give them a different assignment this is how to do it. You must first click on the building or roadblock that contains some officers or biologists. By clicking on the cop or biologist tabs in the pop up you can get access to the units stored in that building. Then by using the arrow icons you can select a number of units which can then be given new orders. 
 
 
 
 
                                                                                
 
 
Unselecting units
 
To unselect any selected units simply click the left mouse button.
 
Ordering Units
 
To give any unit an assignment you simply have to have a unit selected and right click on the object you want to assign them to. Ordering units does not unselect them however so you should unselect them before giving orders to other units. 


  
Sending Units on Patrols
 
To make a unit patrol the city you must first give it a path to patrol. To do this you must have a unit selected. First, Click on the patrol button in either the HUD or the character pop up. Your cursor should change to show that the patrol mode has been selected. To set way points you must left click at different positions on the streets to set markers. As you do this a small symbol will appear showing your selection. When you have set all the way points you want to be patrolled click the right mouse button to initialise the patrol for the selected units. They will now patrol that route forever until you assign them new orders.


Setting Quarantines, Lockdowns and Airstrikes
 
There are two ways to assign these actions to buildings.
 
The first way is to click on the building and in the building info pop-up click the button for the action you wish to apply to that building. If the action is the quarantine or lockdown, these actions can also be cancelled by clicking the button again. 
 
The second way to first select the action you want to apply and then select the building to apply it to. To do this select the action on the HUD actions menu, your cursor will change to reflect the action. Then left click on the building you want to apply it to. 
 
The actions are context sensitive. If you already have a building selected and then click on one of the HUD action buttons the effect will be instantly applied to the building selected as though you clicked it in the pop up box.
 



                                                                         

 
The Overmap
 
Sometimes a new perspective can help you understand a situation. By pressing the "m" key on your keyboard or clicking on the icon above the minimap you can switch the camera to a top down view that will let you easily see the situation in the city. Pressing the button or clicking again will return the camera to normal.


  
 
 
Effective use of Roadblocks, lockdowns and Quarantines
 
The roadblock is one of the most useful tools at your disposal. Thoughtful and timely placement will allow you to have a great deal of control over the flow of civilian traffic in the city.  One very useful feature of the roadblock is that you can set the direction of travel that civilians can pass through. It can be changed on the roadblocks pop up menu. By using this feature you can potentially evacuate a great number of civilians from a section of the city and not allow anyone back in. The direction of travel can be changed at any time so it is a good idea to block off an area that has infected people, allow people to leave the area until the infected civilians start moving and at that point stop people from passing through the roadblock. 
 
The roadblock is a useful tool but don't forget to reinforce it if you want it to be effective. 
 
 
Lockdowns are another useful tool, primarily when used in conjunction with a roadblock. A lockdown will evacuate every person from a building and lock the doors so no one can get in anymore. Lockdowns are a little different from the others because they don't need reinforcements to make them effective. If you know that an infected person is on their way to a particular building you can evacuate that building and reduce the chance of them getting infected. 
 
Combining lockdowns and direction of travel  means you can evacuate an area of the city and reduce the impact infected person will have on the area.
 
A quarantine is like a roadblock for a building and they're the most effective means available to stop the spread of the virus. If you know a building has an infected person, quarantining the building should be the first action you take. Sending biologists in quickly means you can contain the spread of the virus and save the infected. You must remember to reinforce them with cops as well so that no one can get in or out. 
 
Quarantines are great but if you can't stop the infected people from leaving them they quickly become useless.
 
 
Panic is your enemy

Every civilian has a panic rating that reflects how worried they are about the current situation. Panic is something that is usually overlooked when playing the game but it does have a notable impact on the game. Civilians that are very paniced are much more likely to break quarantine and break through roadblock. They will move quicker through the city be much harder to contain. Having cops patroling will reduce the panic of every civilian near them. Destroying a building though will severy panic anyone near it. If you make an effort to keep panic at a manageable level you will find that the situation becomes easier to handle. 
 
Cops are your friends
 
Cops are your most abundant resource but even with that said number of cops available for deployment is very limited. While you do have control over all the law enforcement in Manhattan there is only a single precinct within the area the player must contain. It takes time for cops from other precincts to get to your location so you have to do your best with your limited resources until they get there.
 
The primary role of the cops is to reinforce your barricades. Whenever you set up a roadblock or quarantine it's created instantly but is unmanned. Unmanned roadblocks and quarantines can be broken through very easily. To prevent this from happening and maximise the effectiveness of the barricade, cops can be assigned to guard them. The more cops that are assigned to a roadblock the stronger it becomes until no one can pass through. 
 
You must remember though that New York is a city and in a city there is always more than one way to get to a destination. An single impenetrateable roadblock is useful but multiple moderately strong roadblocks can be even more useful. The resources available are very limited and correctly deciding where to use them and (more importantly) when to use them is the key to doing well.
 
Cops can also be sent on patrol around the city. You can make any number of cops walk on a set path around the city and this is also a useful function for your cops to perform. Having cops walk through the city will re-assure the public and reduce their panic levels. As said before the less paniced a person is the less likely it is that they will do something unexpected like break through a roadblock. 
 
Biologists are vital
 
The second human resource the player has at their disposal are Center for Disease Control Biologists. These are an even rarer resource than the cops. As you can guess by their title, they specialise in stopping the spread of the disease. The biologists can perform the same actions as the cops (namely manning barricades and patroling the city) but they have completely different effects on the public. When a biologist is near an infected person they perform very 3 important actions. First, if the person is infected but you don't yet know that they are infected, the biologist will give a boost to the early detection of the infected people. Second, having a biologist nearby reduces the chance of the infection spreading. Finally, having a biologist near an infected person has a chance to save the infected person from dying (It is not a very good chance however so don't rely on it).
 
The biologists effects stack in the same way as the cops. The more you have in a given area the greater effectiveness awarded. Patrolling biologists however are primarily used for detection. The Biologists effectiveness is greatest when manning quarantines.
 
 
Take your time
 
This game is an RTS meaning that decisions must be made quickly and you will have to adapt to changing situations as you go. Managing this small subsection of manhattan is no easy task, to help with this though we have added Planning Time. Planning Time will freeze the game for up to thirty seconds and give you a chance to issue orders and position barricades without worry of the situation changing while you're deciding on your actions. Planning time will regenerate when not being used and can be a life saver when things start to get out of control so don't be afraid to use it, it's your best friend.
 
Blow it up
 
Finally we have the airstrike, the airstrike is lot of fun to use (Who doesn't like blowing up buildings) but using it will have a large negative impact on your score. When the airstrike is initiated, a stealth bomber will fly overhead and destroy the selected building. This will turn the building to rubble and kill every person inside the building (cops and biologists included). Used correctly though it can have an overall positive result on your score. It is designed to be used as a last resort if the infection is spreading out of control. If by chance you have managed to contain most of the infected in one building it can be beneficial to destroy that building and eliminate the majority of the infected people, effectively containing the spread of the infection. Bombing a building though will eliminate any chance you have of getting a very high score.