MoveTogether: Exploring Physical Co-op Gameplay in Mixed-Reality

Paper Title

MoveTogether: Exploring Physical Co-op Gameplay in Mixed-Reality

Publication Info

• Topic area: Mixed-reality co-op gameplay with shared physical props.
• Keywords: Mixed-reality, co-op games, physical interaction, haptic feedback, shared props, collaboration, embodied interaction, teamwork, tangible interfaces, user experience.

Background and Problem

• Problem / challenge: Current co-op games primarily rely on virtual collaboration with separate controllers, limiting embodied teamwork and physical interaction in shared spaces.
• Significance: Enhancing physical collaboration in co-op games can foster richer teamwork, communication, and mutual awareness, leveraging nonverbal and haptic cues.
• Motivation and related work: Prior work has explored virtual co-op games and tangible interfaces but has not systematically examined the design space of shared physical props for co-located gameplay. This paper addresses this gap by introducing a novel physical co-op mechanic.

Solution

• Proposed approach: MoveTogether, a gameplay mechanic where two players jointly operate a single tracked prop, adding a shared physical communication channel to visual and audio cues.
• Novelty:
  1. Introduction of a shared physical prop for co-op gameplay, enabling haptic communication and mutual constraint.
  2. A design-space exploration identifying prop dimensions (e.g., size, geometry, material) and interaction primitives (e.g., moving, rotating, squeezing).
  3. Empirical comparison of physical vs. virtual co-op, showing benefits in coordination, safety, and user experience.
  4. Open-sourcing of the MR game for further exploration.
• Procedure and key techniques:
  1. Conducted a workshop with 10 professional designers to explore prop and interaction design dimensions.
  2. Developed an MR prototype using a ring-shaped prop and implemented co-op gameplay scenarios.
  3. Conducted a within-subjects user study (n=16) comparing physical and virtual co-op conditions, analyzing subjective preferences, behavioral observations, and qualitative feedback.

Results

• Concrete findings:
  • Physical co-op enabled finer-grained coordination, reduced collisions (91% fewer person–person collisions), and increased task-related verbal cues (2.4x increase).
  • Participants rated physical co-op higher for collaboration (94% preference in Trampoline Scenario, p < .001), sense of achievement (88%, p < .001), and engagement (81%, p < .01).
• Advantage over baselines:
  • Physical co-op outperformed virtual co-op in fostering tighter collaboration, denser communication, and enhanced spatial safety.
  • Participants preferred physical co-op for its shared emotion and joint completion, though some valued the autonomy of virtual co-op.
• Experiments / evaluation:
  • Two gameplay scenarios (Trampoline and Bubble) were tested under physical and virtual co-op conditions.
  • Metrics included subjective ratings (10-point scale), behavioral coding (collisions, verbal cues), and qualitative interviews.
• Limitations and future work:
  • Focused on two-player pairs; future work should explore larger groups and ad-hoc teams.
  • Evaluated a single prop type; additional studies could examine diverse prop designs.
  • Did not isolate the effects of shared physical and virtual elements; future research could explore alternative configurations.

Summary

MoveTogether introduces a novel physical co-op mechanic using a shared tracked prop, enhancing collaboration through haptic communication in mixed-reality games. A design workshop identified key prop dimensions and interaction primitives, while a user study demonstrated significant benefits of physical co-op over virtual co-op, including improved coordination, safety, and user experience. This work opens new possibilities for embodied teamwork in co-located gameplay and provides a foundation for future exploration of shared physical interactions in MR contexts.