Concept Design Document: Electro Defense

Concept Design Document | Alexander Chatzizacharias

1.1 Game concept

Our goal is to create a game which will make students interested in physics and show the how fun you can have while playing with electrical circuits and electrical devices. Our first concept is Electro Defense.

Electro Defense is a concept highly based on the successful tower defense games. Your goal is to protect your base by buying, building and using the power of electricity to defeat the incoming waves of enemies.

For towers the player uses electrical machines. Examples are an electrical tower or a spotlight. In the proof of concept we use 5 different towers, an energy absorber, a spotlight, an electricity tower, a laser beam and finally the electrical mat. The player has to use the shop to buy parts for the towers and then assemble them to create the tower he wants to create. In the following image you can see a raw sketch of the screen when the player is in game.

1.2 Feature Set

The game will have multiple features that will make it appealing to the target audience. First off, tower defense games are extremely popular and relaxing. The player can jump in and play whenever he feels like too. Also the player does not need a lot of “skill” to defeat a tower defense game. Logical thinking and quick reaction should be enough to beat the game.

The key feature of the game is the building of towers. The player will have to build towers and strategically choose where to place the towers. The game world does not have fixed places where the towers can be build. The player has the freedom to choose where he wants a tower and place it there.

The enemies will come in waves. This means that between each wave the player has some time to think about his next move and where to place towers. Because there is no fixed path for the enemies the game will feature a path finding system which enables the enemies to avoid towers. Like this the waves will become unpredictable and more challenging.

The game will also have a shop. In the shop the player will be buying parts. Parts are needed in order to build towers. The shop will be the stop station between each wave. In this brief period of time the player will have to choose which parts he wants to buy and like which towers he wants to build and where. In the following sketch you can see how the shop and the tower menu could look like.

The game will also have a wiring system. That means that the player will have to buy multiple meters of wires to build a tower where he wants to. That means, the farther away he wants to build a tower from his base, the more meters of wire he has to buy.

The game will also feature a tower overloading system. This system will allow the player to empower a tower by sending more electricity to it. Overloading is a double edged sword though, send too much electricity and the tower will explode!

Finally the game has a serial and parallel circuit system. If the player puts the towers in serial circuit the towers will become stronger and the player will have to spend a lot less on wiring. If a tower overloads though in the serial circuit, the rest of the towers in the circuit will also collapse. If the player chooses to use a parallel circuit he will have to buy a lot more wiring and lose some damage but in the other hand he will not have the risk of losing multiple towers if one tower overloads.

In the following sketch you can see the concept of serial and parallel circuiting.

 

1.3 Genre

The game is a tower defense game. Tower defense games are an offspring off the original RTS (real time strategy) games but with a lot of limitations. The player does not have the freedom of building units and sending them out to attack. The player is stuck at building defensive towers to protect his own base from attacking waves of enemies.

1.4 Target audience

The target audience for this game are children that go to the 2^nd and 3^rd year of their high school. Our goal is to create a game which will show these children how much fun electrical engineering can be and showing them that choosing for the BETA side later in the 4^th year could really pay off.

1.5 Controls

The player plays the game with the mouse. He clicks the tower he wants to build or the part he wants to buy and then chooses where he wants to place the tower. The shop can be accessed through hotkeys or an in game tab.

1.6 Look and feel

The game will have a cartoonish style. Such a style is most appealing to our target audience. The enemies will be more comical than frightening and the towers will also look cartoonish. The interface will support this visual style by also being cartoonish with brightly colors. In the following images you can see some examples of the cartoonish style.

2.1 Gameplay

The objective of the game is to prevent the enemy waves from reaching your base. The player achieves that by building towers in the path of the enemy waves which damages/slows the enemy’s.

The game progresses fairly simple. Each wave has a set amount of enemies. After the enemies are defeated the player has a set period of time to choose which towers he wants to build and where. Each wave has an increased number of enemies and eventually new and stronger enemies will appear.

The challenge in the game is to keep up with the increasing difficulty of each wave. The player has to use strategic placing to change the path of the enemies and quick reactions to empower his towers and quickly eliminate the enemies who oppose the greatest threat. The game is very strategical and the player will have to use a lot of trial and error until he discovers the best strategy for each wave. Here are the major choices the player will have to make between each wave:

- How is my money flow?
- Which tower?
- Where?
- Parallel circuit or serial circuit?
- How much wiring do I need?
- How much power should I send to the tower?
If the right choices are made the player will progress to the next wave.

2.2 Mechanics

The mechanics of the game are pretty simple. In the next sketch you can see a chart of how everything is connected within the game. In the following pages the explanation will follow.

2.2.1 Physics

The game makes no use of physics. Because it is played from a top down view there is no need to use physics within the game.

2.2.2 Movement

There are 3 different sets of movements within the game.

 Firstly we have the mouse cursor which is controlled by the player. The player can freely navigate the cursor wherever he wants. While there is an ongoing wave the player cannot enter the shop. He can only build towers and send more power to the towers.

The second set of movements are the enemies. The enemies move from left to right to heading to the base. The enemies are controlled by a basic path finding AI. When an enemy unit walks up to a tower he goes left or right and avoids the tower.

The last set of movements are the towers and “bullets”. The towers can be drag and dropped to the specific location that the player whishes to place the towers. The towers (once placed) then face the enemy which is in the attack radius and then shoot them. The bullets then travel to the enemies and eventually damage them.

2.2.3 Objects

There are multiple objects within the game. Namely towers, and tower parts. Each tower needs specific parts to become usable. Building the tower then consumes the parts & the needed currency. Each tower can be upgraded 3 times. Each upgrade then increases the effect of the tower. Each tower can also be empowered by sending more power to the tower. The tower effect increases the more power you send at it, but if you send too much power the tower overloads and you lose the tower.

Clicking on a tower opens up the tower menu. In the tower menu you can upgrade the specific tower and decide how much power to send to the tower.  In the following sketch you can see the layout of the tower menu and under the sketch are some examples for a couple of towers.

Spotlight: Blinds and slows the enemy. Each upgrade increases the slowing effect.

The player sends power to the spotlight, the incoming energy will be calculated with the formula I = √ (P/R)

 I refers to the power of the tower.

Slowing (1) 15% +10% of the incoming power
Slowing (2) 25% +10% of the incoming power
Slowing (3) 50% +10% of the incoming power

Parts needed:
Steel
Light bulb

Electricity-tower: Damages the enemy. Each upgrade increases the damage.

The player sends power to the electricity-tower, the incoming energy will be calculated with the formula I = √ (P/R).

I refers to power of the electricity-tower.

Damage (1): 5 +10% of the incoming power
Damage (2): 15 + 10% of the incoming power
Damage (3): 30 + 10% of the incoming power

Parts needed:
Steel
Transistor

Laser-Beam: Damages the enemy. Each upgrade increases the damage.

The player sends the power to the Laser-Beam, the incoming energy will be calculated with the formula I = √ (P/R).

 I refers to power of the Laser-Beam.

Damage (1): 10+10% of the incoming power
Damage (2): 20+10% of the incoming power
Damage (3): 40+10% of the incoming power

Parts needed:
Steel
Prism

Electrical mat: The super weapon of the game. Not upgradeable.

The player places an electrical mat on a set of 9 tiles. Any enemy (except bosses) that steps on the mat is immediately defeated. Each time the mat kills an enemy the player loses some of his power.

The game will also have multiple items that are needed to build the towers. Here are some possible items:

Lamp

Prism

Transistor

Steel 

Wire

2.2.4 Combat

The combat in the game is very linear. There is only damage calculation. The damage that needs to be calculated is the damage between tower and enemy, and enemy and base. The damage each tower inflicts on an enemy is fixed and the HP of the enemy is also fixed.

2.2.5 Economy

The game will have two kinds of currency. Money and Power. Money will be used to buy items and towers, while power will be used to empower towers and gain money. The player gains power by killing enemies. That is the work of the energy absorbing tower.

Energy-Absorber: Absorbs energy from nearby defeated enemies. Each tower upgrade expands the radius of the absorber. The defeated enemies will drop a random amount of “electricity”. The absorber converts the electricity into power with the formula: P = I^2* R.  R is a fixed number.

Like this the player the player will be forced into strategically placing energy absorbers to keep his power flowing.

In the shop the player can sell power for money. Like this we force the player to be careful with sending much power into his towers because that again limits his cash flow.