# Bastion

_The Watchers Lament_

# Game description and functionality

Bastion is a Tower Defense type of game.

The game offers the player various missions that he can play.
In each mission the player is tasked to defend a path going from the entrance of the map to exit of the map.
Each mission is split into multiple rounds. Each round consists of two phases:

1. Phase 1 (Buy phase) - The player can buy towers and place them on the map.
2. Phase 2 (Combat phase) - In this phase there the enemies spawn at the entrance of the map and start moving towards the exit. The towers will attack the enemies and try to stop them from reaching the exit. More enemies may spawn during the combat phase.

For every creep killed by the player, the player will receive Gold resource.
Every time a level is finished (Combat phase completes) the player will also receive one Gem.
The player can use the Gold to buy more towers or upgrade the existing ones.
If a creep reaches the exit, the player will lose a some health points (HP).
If the player loses all his HP, the game is over and the player has lost.
If the player completes all the rounds of a mission, the player wins and receives a Score which places him at a leaderboard.

# Functional description

## Game start

The game starts with a Main menu screen.

## Main menu screen

The main menu has the following options (buttons):

1. Play - Starts the game by going to the Mission selection screen
2. Exit - Exits the game

## Mission selection screen

The mission selection screen has the following content:

1. List of missions where the player can choose one mission to play by going to the Mission screen
2. Back button - Goes back to the Main menu screen

## Mission screen

Mission screen is reached when the player selects a mission from the Mission selection screen.
The Mission screen has the following content:

1. The map of the mission (image representation)
2. The path of the creeps (line on the map)
3. Amount of waves in the mission
4. The entrance and exit of the map (marked on the map)
5. Leaderboard - Shows the top 10 players with the highest score for the current mission
6. Starting Gold - The amount of Gold the player starts with
7. Starting Gems - The amount of Gems the player starts with
8. Button to start the mission (Game screen - Buy phase)
9. Button to go back to the Mission selection screen

## Game screen

Every game screen (Buy or Combat phase) has the following content:

### Game map

The map is covering the majority of the screen (80%). There is no zooming or panning. Depending on the map aspect ratio, the map may be cropped on the sides.

### Options Panel

The options panel is opened by pressed the options button located on the top left corner. The options panel allows the player to:

- Restart current wave
- Restart mission
- Return to main menu
- Close panel (opening it automatically pauses the game)

### Sidebar

The side bar is located on the right side of the screen and takes up a lesser amount of the screen (20%). It's functionality changes based on whether you are in the buy phase or combat phase.

### Topbar

The top bar is located to the left of the sidebar and shows you your current HP, Gold, Score and Wave/Total Waves.

## Game screen - Buy phase

During the buy phase (has no time limit), the player may spend their Gold to purchase towers and use their Gems to empower their towers in specific ways depending on the gems used.
After the player has finished spending their resources/strategizing, they may end the Buy phase by pressing the "GO" button in the bottom right corner (sidebar).

### Sidebar - Buy phase

The player starts with 200g and 100 HP.
During the buy phase the sidebar is split into 2 tabs, the Tower menu and the Gem bag. The tower menu contains towers which you can place on the map grid.
You may purchase towers with Gold, and certain towers can be empowered with Gems while others can not. Towers themselves can not be upgraded instead you upgrade your Gems.
Gems are given at the start of the buy phase (specifically only 1 picked out of 3) and are subsequently placed into the gem bag.
From the Gem bag they can be slotted into a tower, upgraded or combined with other gems.

_(razmisljam o tome da se gemovi na pocetku buy phasea moraju kupit i/ili mogu se rerollat i/ili da se "upgradeani" ili vec "craftani" gemovi isto mogu kupit)_
_(takodjer razmisljam da ima market tower koji se moze buildat)_

## Game screen - Combat phase [WIP]

### Sidebar - Combat phase [WIP]

## Towers

Towers are the buildings you build on the map grid which attack/help you in defeating the creeps that are traversing the path.
They always have a circular range around them within which they will attack creeps.
Placing a tower on the grid costs a certain amount of Gold defined by the tower, while empowering it via Gem does not cost anything (Gems are not consumed, more like "slotted" as they can be repossesed).
Towers on their own can not be upgraded, only the Gems that are empowering them can be.
Not all towers can be empowered and they would serve more for utility purposes instead of attacking creeps.

### Shooting Tower

Basic tower that shoots 1 projectile at the closest creep.

- Damage: 1
- Attack Cooldown: 2s
- Empowerable: Yes
- Cost: 100g
- Range: 100 pixels

### Circular Tower [WIP]

### Line tower [WIP]

### Chain tower [WIP]

## Map grid [WIP]

## Creeps

Creeps are the "things" that travel down the pre determined path of the map from the beginning to the end, which the towers will automatically target and which have a set amount of HP.
Upon reaching the end of the path, they will take away the amount of HP they have from the player's HP (if creep clears the path with 5 HP, player 100 -> 95 HP).
There are multiple types of creeps with varying amounts of HP, movement speed and special attributes (only vulnerable to divine attacks, etc).

### Basic Creep

- Health: 2 HP
- Speed: 35 pixels per second
- Special attributes: None

### Quick Creep [WIP]

### Bulky Creep [WIP]

### Undead Creep

Requires tower to be empowered with a divinity gem to deal damage, otherwise immune to damage.

- Health: 5 HP
- Speed: 40 pixels per second
- Special attributes: Undead, Weak to Divinity, Resistant to Soulforge

## Creep waves [WIP]

## Resources

### Gold

Gold is the resource you get per every creep killed. Every creep decides how much Gold it gives upon its death. Gold is used to purchase towers and alter the map.

### Gems

Gems are not a number resource like Gold is, rather you earn one of the possible Gems upon completing a round. They are placed in your Gem bag which is accessible via the sidebar.
Currently there are 6 Gems:

1. Fire Gem (#FF0000) (fire)
   - Description: A firey gem found inside the ancient ruins of a lost volcano dwelling civilization, this gem is infused with many eons of firey, quicky, volcanic energy to deliver fast and burning blows to all creeps.
2. Yeti Gem (#0000FF) (ice)
   - Description: [WIP]
3. Titalium Gem (#FFFFFF) (white)
   - Description: [WIP]
4. Soulforge Gem (#00FFFF) (cyan)
   - Description: [WIP]
5. Rift Gem (#FF00FF) (purple)
   - Description: [WIP]
6. Divinity Gem (#00FF00) (green)
   - Description: [WIP]

_(idealno 6 \* 4 combos)_  
_(impossible combos:_  
_soulforge + divinity_  
_rift + titalium_
_)_  
_fire + yeti gives frostfire_
_(kasnija ideja svakih 5 rundi dobit "utility" gem koji mozda ubrzava attack speed ili daje neke specificnije buffove)_  
_(ideja: merchanting gem, gemovi koji su kombinirani s ovim gemom kostaju 10% manje, round down)_  
_(ideja: scavenger gem, gemovi koji su kombinirani s ovim gemom 25% vise golda nego sto creep normalno daje, round up)_

### HP

HP (Health Points) is the resource that you always start with 100 of and you must keep it >0 upon finishing the final round to win the mission.

### Score

# Data structures and algorithms [WIP]