Game Features

The overall game mechanic - Inspired by Plants vs Zombies

Map

MUST HAVE

1. Fixed lanes along which towers fire and enemies move towards the resource extractors (base)
2. The game arena is separated into a grid with discrete placement positions
3. Aliens will come from one side like in plants vs zombies; Using hybrid side/top-down view
4. Players will have a certain amount of time to place towers and defences after each wave
5. HP will be human lives remaining (if a zombie gets through all defences it will take a certain amount of lives depending on which zombie is getting through.

(Isometric and multiple sided defence were considered:

• Isometric view adds some complexity to the implementation, and it was thought would require higher quality assets.
• Multiple sided defence was discounted due to the concern about having mobs animated from different angles, having too many lanes which would require many more towers to defend, and screen size. The entire map was to be shown on one screen without panning, which cuts down on usable screen space)

Future features

F1. Design multiple levels

Towers (not including attack)

• Towers can be created and placed on tiles on the map
• Towers block movement through the tile
• Multiple towers can be placed along one lane
• Towers can be damaged and destroyed by mobs (towers have health)
• Tower appearance will differ depending on type, amount of health left
• Tower animations for construction state, firing, destruction

MUST HAVE

1. Towers that damage enemies using different weapons/effects
2. Defensive fortifications such as walls/armour
3. Towers have other abilities
   • Passive towers (walls) that have high health but no attacks
   • Towers that have direct fire capability
   • Towers that have indirect fire capability ('mortars')

Future features

1. Planets buff/restrict towers (Should this be in the map section?)
2. Add more types of towers (different types of weapons/defensive mechanisms)

(Tower and Mob) Projectile mechanic

• Projectile Design

  • Starting point

  • Speed

    • Need to think about a scalable interval
    • Fluidity in movement

  • Direction

    • Starting off with linear
    • Adjustability during movement
    • Pivot from starting point with respective angle

  • Collision

    • Disappear at contact. Deals damage/Apply effect
    • Continues after contact. Deals damage/Apply effect
    • Bounce at contact
      • Randomised Direction
      • Targeting Direction
      • Default spacing-value on contact should be adjustable

  • Duplication

    • Spacing of duplication
    • Direction

  • Size

    • Hitbox (of mob/tower)

MUST HAVE

1. Projectiles from both towers and enemies that cause damage

Future features

1. Projectile animations
2. Different projectile types

Multi‐target Projectiles

Build mechanic

MUST HAVE

1. Towers and fortifications can be built and placed - implement a build menu
2. Towers and fortifications take time to build - implement a build delay?

Future features

1. Towers and fortifications can be upgraded/stacked - implement an upgrade menu?

Mobs - General

MUST HAVE

1. Mobs can move in a straight line along the row in the grid (mobs will be animated as they walk)
2. Mobs have a health bar and can take damage from projectiles from the towers (the health bar won't be displayed, but instead the graphic of mob will change - as they take more damage, they appear more "beaten up" etc.)
3. Mobs can send projectiles and damage towers (which also have their own health bar)
4. Certain mobs may have immunity to certain attacks from towers (those projectiles wouldn't affect their health bar)
5. Each mob has its own set of properties - speed, starting health bar, amount of damage received from a certain projectile, amount of damage given when firing its own projectile
6. Mobs will come in waves

Future Features

1. Mobs can change lanes/redirect around towers (direction is randomised when they encounter a tower)
2. (Maybe) Human engineers are selectable/controllable units that build/repair/upgrade/buff towers
3. Mobs have different elemental effects

a. Different planets have properties that affect the mobs (may affect the projectile they send, how much damage they take from other projectiles)

Mobs - Bosses

MUST HAVE

1. Bosses will come during significant waves

Future Features

Economy mechanic

MUST HAVE

1. Credits/resources earned by killing enemies
2. Resources extracted over time also provide credits
3. Random event triggers for effects such as double damage or more powerful enemies

Future features

(Add features here)

HUD

1. Health and gold will always be shown with gold being displayed on a button that opens the shop when clicked.
2. When towers are clicked a small pop up will display the possible upgrades with costs etc.