Game Design Document

  1. Introduction
  2. Genre
  3. Audience
  4. Story
  5. Platforms
  6. Setting
  7. Gameplay
  8. Graphics
  9. Actors
  10. Controls
  11. GUI
  12. HUD
  13. Levels
  14. Health system
  15. Weaponry
  16. Bonuses
  17. Multiplayer
  18. Sound
  19. Options
  20. Artwork

01 Introduction

Mission: Defender
Mission: Defender is a small and simple independent game for various mobile and gaming platforms.

The title is currently under development by Contour.  Stay tuned to get more from our news.

02 Genre

Mission: Defender is sci-fi driven 2D action game.

03 Audience

If you want to save the Earth from disaster right now, then “Mission: Defender” is for you!

04 Story

Astronomers from different countries discovered a huge threat from space, which is about to destroy the planet Earth. Different space pilots called to the rescue. You are one of them. Now the planet should be safe.


Right, captain?

05 Platforms

Ideally, “Mission: Defender” targets all possible mobile and gaming platforms. The list of the platforms under consideration is the following:

  • Android smartphones
  • Android tablets
  • iOS smartphones (iPhone)
  • iOS tablets (iPad)
  • Windows Phone
  • Tizen
  • Playstation 3
  • xBox 360

The list is not complete and will be probably changed at any time. Feel free to follow the news in our development blog (coming soon).

06 Setting

The setting of the game is space/sci-fi.

The environment is endless space.

07 Gameplay

You start the game as a pilot on a super powerful spaceship which has been built for this particular case. Your primary goal is saving planet Earth from being blown up by asteroids. It is very responsible task and it is not so easy to fight everything alone. No worries, there is some help from your partners on Earth, which you can call when everything is ready.


Your activity includes:

  • flying
  • shooting
  • calling backup
  • dropping helpers (drones)
  • collecting bonuses

08 Graphics

Basic gameplay:



Multiplayer: Survival mode gameplay-screenshot-multiplayer-survival-mode


Multiplayer: Backup mode


09 Actors


Primary actors:

  • player’s spaceship
  • planet Earth
  • asteroids
  • asteroids bosses
  • bonuses

spaceship             asteroid-3asteroid-boss



Secondary actors:

  • backup rocket
  • drones


Boss system:


step 1



step 2


10 Controls

The spaceship is controlled as following:

  • On mobile devices players control spaceship using the on-screen controls. Additional option is to control the spaceship using built-in accelerometer, but this option is still under consideration.
  • On gaming platforms (Playstation, xBox etc.) players control spaceship using gamepads.


11 GUI

The game GUI (Graphical User Interface) consists of the following parts:

Main menu:

  • Play button
  • Options button
  • Credits button
  • Exit button


  • Rolling briefing text
  • Choose drone slider
  • Start button
  • Back button


  • Spaceship direction control
  • Fire button
  • Drone release button
  • Backup rocket button
  • Pause button
  • Mini-map of the scene

12 HUD

In-game HUD (Head-Up Display) consists of:

  • Radar (minimap)

13 Levels


14 Health system

There is no health system. Any collision with an asteroid results complete destruction.

  • Spaceship collides with an asteroid = explosion = GAME OVER!
  • Earth collides with an asteroid = explosion = GAME OVER!

15 Weaponry

Weaponry system of the player’s spaceship includes:

  • Lightning drill (primary weapon)
  • Drones (secondary weapon)
  • Backup rockets (extra weapon)










16 Bonuses

Bonuses come from the endless space regularly.

Collecting them give lots of advantages:bonuses-list

Attention! The bonuses are fragile and destroyable.


more to come…

17 Multiplayer

Menu tree sequence scheme:


Multiplayer mode 1: Survival


  • Up to 4 spaceships players + 2 backup players
  • Control only spaceship weaponry
  • Different drones allowed




Multiplayer mode 2: Backup



18 Sound

Feel free to taste the first bit of soundtrack for the game:

More to come…

19 Options

The “Options” part includes:

  • Left handed / right handed view
  • Vertical / horizontal view
  • Sound level

20 Artwork