The Second Set of Biometric Experiments
A second series of tests was conducted two months after the initial experiments. The aim of this second series of tests was to understand how a player's performance develops during the first 10 minutes of gameplay.
An important point to clarify is that in the competitive version of the game, the walking speed of the paper creatures increases incrementally after a specific number of creatures have been correctly recognized. The idea behind this design parameter is that if our fantastic creatures are not properly fed, their actions become more frenzied as they grow hungrier in their search for food. In this phase of the testing, the development team wanted to find an ideal balance between the initial speed of the game and the rate of acceleration as players progressively gain skills during their advancement of the game. Specifically, we wanted to find answers to the following questions:
- Does the game allow players in our target audience to be proficient enough to endure play-sessions of five minutes after three or four games?
- Does the game make our players excited but not anxious?
- Do players have a generally positive reaction to the reaching of the Game Over state (which needs to be perceived as fair and encouraging)?
Visual Results for the Second Set of Tests
The graphs below visualize the test results of one of the 14 test subjects that was tested in the second phase of experiments. Each dot on the graph represents a different beast. Blue dots represent beasts that were walking at basic speed, and red dots represent beasts that were wobbling faster than the basic speed.
In the test version of Gua-Le-Ni, the paper beasts were accelerated after the appearance of every four specimens. The vertical line on the graph represents a Game Over state, after which the game resets.
Skin Conductivity graph for test subject 35. Every Game Over (vertical red line) corresponded with a stress peak. As readable in the graph, the first game lasted a little more than one minute, the second a little less than two minutes, and the third almost three minutes.
The first graph tracked a dimension called skin conductivity of one of our test subjects. Skin conductivity provides a basic understanding of how tense or excited a test subject is by tracking the variation in moisture of his or her skin.
The results visualized in the graph above show that during the very first game, which lasted for approximately one minute and 10 seconds, Test Subject 35 was able to successfully categorize all of the beasts at the basic speed level, but failed at the first beast that would wobble faster than the initial speed. The results of the two following gameplay sessions show that excitement levels grow slightly as the difficulty level is increased, and reach extremes at Game Over states.
A game design reading of the skin conductivity graph of test subject 35 demonstrates that the ability to deal with complexity and speed progressively increases. In particular, subject 35 reached a three-minute gameplay session at her third game. This result corresponded with the aspirations of the development team and was regarded as an early success.
Overall, the test results showed that the duration and intensity of the game broadly matched the design intention of empowering the player to cope with slow beasts straight after the tutorial and to reach three-minute gameplay chunks within the first five minutes of gameplay. Nevertheless, combining the results of the biometric testing with the results of traditional questionnaires, I decided to make the game slightly slower. In the released version of the game, the rate of acceleration was also lowered and smoothed.
The second graph, by contrast, shows the variations of a second biometric parameter for the same gameplay session and in the same test subject tracked above. The second graph maps the electrical activity in the Zygomaticus Major muscle (responsible for smiling) during gameplay.
The activity of the Zygomaticus Major (smiling muscle) for test subject 35 during the same three games analyzed above. Every Game Over that was associated with stress peaks in the skin conductivity chart corresponds to a smile in this graph.
A combined reading of the graphs shows that the Game Over condition always invoked a smile in the test subject. When players were questioned about this in the post-gameplay interviews, we learned that such smiles were due to the fact that players could manipulate the cubes in an attempt to categorize the beasts until the very last pixel of the beast's tail is visible on the screen. This feature of the game produced a positive attitude that encouraged players to replay the game. The design feature gave the players a feeling of "almost having made it."
Another interesting conclusion that was inferred from the data is that beast configurations in which there was a large size disparity between heads and bodies generated more smiles. These configurations were perceived to be quirkier. The "WART-DOR" (warthog-condor) and the "RAB-PUS" (rabbit-octopus) were the configurations that elicited the most smiles in our test subjects. Although nothing was done with this information, in retrospect, we could have made these types of configurations appear more frequently in the game.