Friday, 27 January 2012

PopCap Case Study: Space of Possibility and Pacing in Casual Game Design

Reading this case study, I thought I had never played a PopCap game... However after some research I realised I had played games developed by Popcap. Bejeweled, Feeding Frenzy, and Peggle are just some of the many successful game titles developed by Popcap. PopCap Games (now a subsidary of Electronic Arts) is an American video game developer and publisher, they are widely known for developing cross-platform "Casual games".

The study stresses that the paper is not about the rules or recipe to create a good casual game but about the principles and critical vocabulary that can be applied to new games and discussions. Again, as I have repeated many times in the past, studies like these help our understanding of the design of games and through understanding, we further our range of knowledge of the tools/principles to craft games...Else how are we to design games if we don't fully grasp the knowledge & tools to create them.

What is a "Casual Game"?
Above: Bejeweled in action...

Games that offer the ease of "Pick up & Play", that have an easy  learning curve for the player to understannd how to play the game can be classed as a "Casual Game". Casual games can have less complicated controls and the gameplay investment can be less time consuming compared to games that are hardcore and require more time investment.

The complexity of casual games can start simple and as the difficulty progresses, greater complexity is achieved by layering simple game dynamics and mechanics through the interaction of smaller objects in the game system.

Establishing A Critical Vocabulary

The study states that it does not offer an in-depth description of the concept of Pacing, "nor offer in-depth description of the vocabulary and its originators, but to make a clipping of the concepts that are necessary". Basically the study covers a range of studies and definitions from other authors that have been "clipped" for the ease and benefit of the reader so that they can better communicate ideas contained in the study.


Pacing is the concept of rhythm within a game, the placement of game mechanics and dynamics relative to the time it is initiated. The study identifies Pacing as "the relative speed at which the different moving parts of the system are put in motion".
Above: The Upper Arch contains all the Lower Arches of Pacing.(M. Venturelli, Figure 2 Diagram, 2009)

Four concepts related to Pacing that happen in the Lower Arch of Pacing and the Upper Arch of Pacing:
  • Movement Impetus: The will of the player to progress through the game and keep playing.
  • Tension: The perceived danger, that the player may become the weaker side of the conflict. Graphics and sound can increase or decrease Tension.
  • Threat: The actual power of the opposing forces on the conflict.
  • Tempo: The time between each significant decision is made by the player. Low tempo can lead to frantic decision-making, compared to High tempo that makes decision-making slow due to impending changes the player is waiting for.
Restricting the Space of Possibility 

Possible actions that players explore as they take part in the game. Collection of all possible actions and outcomes inside the designed space of the game.

Venturelli states that:
" the Space of Possibility increases, [the] Tempo also increases. [The] Higher the tempo the lower Player Impetus."

 Perceivable Pattern of Continuous Learning

The main focus of the methods is to keep a constantly high Player Impetus through the experience. The player must be tempted to agree with the game experience through immersion so that they are compelled to stay in the game. As the player learns how to play the game and masters the play pattern they in turn completely absorb the pattern, therefore the game becomes boring due to recognition of it and constant encounters of it. As designers we can strive to vary the play patterns to a point of balance, else too much frustration from variety and change, in the pattern, can drive players away from the game.

My thoughts on the study

  • Talk about design as principles, not rules or recipe for a game.
  • Keep space of possibilities to a managable size, so as not to overwhelm players at the start.
  • Long-term play is benefited from replacing mechanics in perceivable patterns.
I found this study quite useful because it observed  and highlighted design decisions in  PopCap games and collected many principles from other game design writers, which is good because it made me aware of the authors and their views. The Peggle case study I was most familiar with because I had played it at a friends house and I found it a rather enjoyable game.
The study highlighted:
  • A perceivable pattern was prevailent: each five levels a new ability replaced the current one and each level the arrangement of the pegs changed.
  • The space of possibile strategies varied the overall approach to players decisions and experience through the use of different coloured pegs and obstacles.
 Group Game Case Study 

Time Merc (Build 21) in action...
Time Merc is the group project that I am currently involved in developing. I am responsible for coding parts of the game (player interaction/behaviour, basic AI, wave level spawn pattern etc). The game at its basics is a top down survival shooter. The controls are WASD for movement, mouse movement to aim, and left click to shoot. The first wave of the game starts with 1 enemy that the player has to find and kill to progress through the game.

Time Merc is about an independent time mercenary who has been slung back in the past, to the prehistoric ages. He is on the hunt to detain the time felon, named Runov, that has intentions on changing the past for world domination. The first level starts in the prehistoric age of the dinosaurs, Merc (the Time Mercenary) has to survive past the many waves of dinosaurs and traverse through the lands to find clues of Runov's location and the reason why Runov has travelled back to this particular time period.

Applying the Venturelli's Case Study principles to my group game, I highlighted some game design decisions that links to the study, this includes elements of the game planned for the future:

  •  Movement Impetus
The current wave the player is on and the amount of kills he has to achieve to progress through the level. Other than that, the possibility to explore the map could count, as the curiousty to explore and fulfill objectives by finding a target.
  • Tension
Enemies that chase the players add tension by the perceived danger that the enemy may damage and weaken the player. The player can avoid this by running and shooting before the enemy gets close. Later updates to the game will introduce tension through storyline via a short comic style introduction to the story, on-screen character dialogue, game background music, sound effects, and projectile/enemy animations. The threat of a mass of dinosaurs progressively growing in number each wave level, which adds tension, is very important to the game design else it would not fulfil the game genre of a survival shooter game.
  • Threat
As the player progresses through the wave levels, the amount of enemies chasing the player increases accordingly. The game introduces the ability to pick up upgrades and buffs to survive through the waves to reach the final wave level.
  • Tempo
The first wave level start with 1 enemy as to not overwhelm or confuse the player, it has a clear objective to find and kill the target. The player is given upgrades and buffs from the drops from the dinosaurs and unlocks on certain wave levels.At the start of the game the tempo would be high, then gradually decrease to a low tempo to survive through the waves as the player progresses.
  • The Perceivable Pattern
 The waves, that the player can recognise when he kills a certain amount of enemies he progresses through the wave level and more enemies spawn with recogniseable pattern such as an increase of 2 added each wave.
The group game has some aspects of design principles in the case study, however the it still lacks a fulfilling player impetus, in my opinion, as the current version does not include any puzzles or tasks for the player to achieve/solve. Hopefully, once the game's dynamics and mechanics, through the code. have been refined and balanced we can introduce these aspects of design for the group game.