Effects of a Gaze-Based 2D Platform Game on User Enjoyment, Perceived Competence, and Digital Eye Strain

Title of the Paper

Effects of a Gaze-Based 2D Platform Game on User Enjoyment, Perceived Competence, and Digital Eye Strain

Paper Information

• Subject Area: Human-Computer Interaction (HCI) and Game Design
• Keywords: Eye-tracking interaction, 2D platform game, Digital Eye Strain (DES), user experience, intrinsic motivation, game mechanics, longitudinal study, gaze tracking

Research Background and Issues

• Problems and Challenges

  • The widespread use of digital devices has led to prolonged screen exposure for many users, making digital eye strain (DES) a significant issue, with symptoms such as dry eyes and eye fatigue.
  • Eye-tracking is an emerging interaction technology, but its effects on user experience (e.g., enjoyment, sense of challenge) and health impacts (e.g., eye fatigue) remain less understood compared to traditional input methods like mouse and keyboard.
  • The application of gaze interaction in practical gaming scenarios is still limited, with research primarily focusing on the feasibility of eye-tracking technology and its role in enhancing gaming or immersive experiences. Balancing the enjoyment of gaze interaction with its potential health risks remains an unresolved question.

• Significance of the Research

  • Understanding the complex effects of gaze interaction on user enjoyment, perceived competence, and health is of practical importance for improving game design.
  • Games are seen as a potential medium not only for enhancing enjoyment but also for alleviating digital eye strain through the integration of eye exercise mechanisms.

• Research Motivation and Related Work

  • This study builds on prior research into the application of gaze interaction in games and studies on digital eye strain and its countermeasures.
  • By designing and evaluating a 2D platform game incorporating various gaze-based interaction mechanisms, this study explores the impact of gaze interaction on user experience (enjoyment and perceived competence) and digital eye strain.

Solution

• Proposed Approach

  • Developed a 2D platform game titled "Shed Some Fear," integrating multiple gaze-based game mechanics.
  • Designed an experimental method with a comparative baseline to study the effects of gaze interaction and mouse interaction on user enjoyment, competence, and DES.
  • Introduced eye exercise-related tasks into the game mechanics to test their impact on alleviating eye fatigue.

• Innovations

  • Combined traditional game actions (e.g., jumping, moving) with gaze interaction, incorporating direct control of the user's gaze position and peripheral retinal areas.
  • The first 2D platform game to fully integrate health intervention mechanisms based on gaze interaction (e.g., mimicking eye exercises commonly used in VR).
  • Conducted a five-day longitudinal experiment to comprehensively record user experiences and health-related metrics under different interaction modes, addressing the lack of long-term studies in this field.

• Implementation Steps and Key Technologies

  • Architecture Design: The game was developed using the Unity engine, combined with an open-source webcam-based eye-tracking framework (UnitEye).
  • Game Mechanics: Included gaze-based object manipulation, path illumination using gaze, and "gaze damage" mechanics, making gaze a necessary input method.
  • Experimental Design: To ensure external validity, participants tested the game at home using two interaction modes (gaze + keyboard vs. mouse + keyboard) while recording subjective experiences and objective data.
  • Data Collection and Measurement: Objective metrics such as jump counts and head position were recorded, alongside subjective questionnaires (e.g., user enjoyment, perceived competence, DES scales).

Research Findings

• Specific Outcomes

  • Enjoyment and Perceived Competence:
    • Compared to mouse input, gaze interaction scored higher in overall user enjoyment (Enjoyment Score) and perceived competence (Competence Perception). Notably, over time, gaze interaction enhanced users' sense of skill mastery.
  • Digital Eye Strain (DES):
    • Gaze interaction significantly increased internal visual discomfort symptoms (e.g., blurred vision, eye fatigue) compared to mouse input, while external symptoms (e.g., burning sensation, tearing) showed no significant changes.
    • The custom gaze mechanisms had limited effects in alleviating fatigue symptoms, partly due to the performance of non-commercial eye-tracking hardware and interaction difficulty.

• Advantages Over Existing Approaches

  • Provided concrete examples of gaze-based mechanics, such as designing "static gaze" and "smooth pursuit" as core game mechanics.
  • Proposed new ideas for advancing interaction design by integrating health strategies (e.g., mimicking common VR eye exercises).

• Experimental or Evaluation Results

  • The experiment demonstrated that while gaze interaction increased visual fatigue, it had a significant positive impact on user enjoyment and perceived competence.
  • Additionally, qualitative user feedback emphasized the need to control eye-tracking performance and avoid excessive use of gaze interaction.

• Limitations and Future Directions

  • Limitations:
    • The non-commercial nature of the eye-tracking technology may have limited the interaction experience, and the home testing environment introduced additional variables.
    • The sample size was relatively small (N = 17), with limited participants completing all days under the gaze condition.
  • Future Directions:
    • Further development and validation of specific intervention mechanisms for digital eye strain, leveraging more mature commercial devices to ensure experimental accuracy.
    • Expanding current research through more diverse experiments (e.g., 2.5D or other game types) to explore the potential of gaze interaction as a health intervention tool.