School of Computer Science
University of St Andrews
2019-20
CS4303
Video Games
Practical 1: Particle Command
This Practical comprises 20% of CS4303. It is due on Friday 4th October at 21:00.
The deliverables consist of:
• A report.
• A Player’s Guide for your game.
• The Processing source code for the video game you will write.
Background
This practical is intended to give you the opportunity to learn the Processing
language, and implement some of the concepts from the Physics component of the
module.
The task is to implement in Processing a variant of the classic video game Missile
Command. If you are not familiar with this type of game, your first task is to read the
following summary:
https://www.technologyuk.net/computing/computer-gaming/gaming-landmarks-1960-1985/missile-command.shtml
You can also play the game (requires Flash) here:
https://my.ign.com/atari/missile-command
Overview
Particle Command is a single-player game in which the player controls three missile
batteries, each with ten missiles. Using the missiles, the goal is to protect six cities
from particles (think of these as rock projectiles rather than the missiles of the original
game) falling from above.
The Play Area
The play area is arranged as per Missile Command, as shown in the following
screenshot:


Missile Command. Atari 1980.
The missile batteries occupy the left, right and centre positions on the ground, with
two groups of three cities in between. This general arrangement should remain the
same in your implementation of Particle Command, but the graphical appearance of
these elements is left for you to decide and document.
Waves
The game proceeds in waves. In each, a set number of particles fall towards the cities
with the intent of destroying them. The number of particles should increase with the
wave number so that the level of challenge in the game increases as the player
progresses. The number of waves is unlimited.
The game is over when all cities have been destroyed.
Falling Particles
The particles fall from the sky (the top of the play area). They should have a random
initial velocity, but you should use the wave number to influence the initial velocity of
each particle so as to increase difficulty in later waves. Particles must also be affected
by both gravity and drag, as described in lectures.
If a particle hits a city, the city is destroyed. If a particle hits a missile battery, the
missile battery is disabled for the current wave.
Missiles
Each battery has a stock of ten missiles per wave. The number remaining in each
battery should be clearly visible to the player.
The batteries are controlled independently by the player, who may choose which of
the batteries fires a missile. Aiming is performed via a crosshair as per Missile
Command. The control scheme for aiming and firing is left for you to decide.
In Particle Command, a missile is a particle with a thrust force propelling it in the
direction of its orientation. Missiles should also be subject to gravity and drag. As in
Missile Command, the missiles fired from the central missile battery should travel
more quickly than those fired from the left or right batteries.

When a missile reaches its target position it explodes. Any particles caught in the
blast radius of this explosion should themselves explode. The blast radius of these
additional explosions may trigger further falling particles to explode, and so on.
Additional Features
From wave 2 onwards, the following additional gameplay elements should appear:
• Some of the falling particles should split into two or more separate particles as
they fall.
• Bomber and satellite enemies should appear intermittently and travel the play
area horizontally, periodically dropping additional falling particles.
Scoring
Basic scoring is as follows:
• The player should be awarded 25 points for each destroyed falling particle,
and 100 for hitting the bomber or satellite enemies.
• At the conclusion of each wave, 100 bonus points are awarded for each
surviving city, and 5 for each unused missile.
However, scoring is multiplied according to the wave following the same scheme as
Missile Command:
• Waves 1 – 2: 1x
• Waves 3 – 4: 2x
• Waves 5 – 6: 3x
• Waves 7 – 8: 4x
• Waves 9 – 10: 5x
• Waves 11+: 6x
A city should be restored (if any have been destroyed) for every 10,000 points earned.
Cities are restored at the end of the wave in which the required number of points is
reached.
The current score should be depicted at the top of the screen, as in Missile Command.
Report
Your report should document the design and implementation of your game in detail.
In particular, it should contain an account of your implementation of the physics
involved. Include screenshots that show your game in operation and illustrate its
features.
Marking
The practical will be marked following the standard mark descriptors as given in the
Student Handbook (see link below). There follows further guidance as to what is
expected:
• To achieve a mark of 7 or higher: a bare bones implementation of the game,
consisting of a single wave of falling particles. This implementation should be
adequately described in an accompanying report.

• To achieve a mark of 11 or higher: In addition to the above, the game should
proceed in waves as specified, with an increasing level of difficulty. This
implementation should be well described in an accompanying report.
• To achieve a mark of 14 or higher: In addition to the above, some of the
additional features should be implemented. This implementation should be
well described in an accompanying report.
• To achieve a mark of 17: the full basic specification above must be
implemented and the report written to a high standard.
Extensions
There follow two possible extensions to your game. These are not required to gain a
mark of 17, but at least one extension item (either from this list or of your own
design) must be well implemented and documented to gain a mark above 17.
• In later levels of Missile Command a “smart bomb” enemy appears.
Investigate and add this enemy to your implementation of Particle Command.
• Add sound effects! See the minim library for Processing.
Pointers
Your attention is drawn to the following:
• Mark Descriptors:
https://info.cs.st-andrews.ac.uk/student-handbook/learning-teaching/feedback.html
• Lateness:
https://info.cs.st-andrews.ac.uk/student-handbook/learning-teaching/assessment.html
• Good Academic Practice:
https://info.cs.st-andrews.ac.uk/student-handbook/academic/gap.html