Can We Make Dynamic, Accessible and Fun One-Switch Video Games?
Sebastián Aced López, Fulvio Corno, Luigi De Russis · 2015 · ASSETS '15: Proceedings of the 17th International ACM SIGACCESS Conference on Computers & Accessibility · doi:10.1145/2700648.2811333
Summary
This demonstration paper tackles a significant gap in accessible gaming: children with severe motor disabilities who rely on single-switch input are typically limited to static, time-independent games that lack the dynamic engagement of mainstream video games. The fundamental problem is that traditional one-switch interaction relies on scanning—a sequential selection method that cycles through options—which is inherently incompatible with fast-paced, real-time gameplay requiring rapid decision-making. The authors present the GNomon framework, built on the NOMON interaction modality, which enables creation of dynamic one-switch video games where selectable objects can be positioned freely on screen without requiring a predetermined scanning order. The paper demonstrates two mini games: "One Switch Ladybugs," a training game where children make colorful ladybugs jump to learn the selection mechanism, and "One Switch Invaders," a Space Invaders-style game where players must shoot moving aliens before they reach the bottom of the screen. The latter game would be impossible to implement with conventional scanning interfaces because aliens move independently across the screen. The games were developed in collaboration with speech therapists, physiotherapists, and psychologists from a Local Health Agency in Turin, Italy, ensuring clinical relevance and appropriateness for the target population.
Key findings
Evaluation with eight children (ages 4-14) with severe motor disabilities yielded encouraging results. Seven of eight participants successfully learned to use the GNomon-based interface during their first session, demonstrating strong learnability. In a follow-up session, all children recognized the interface and remembered how to use it, confirming good memorability. The study included children with additional cognitive impairments, and two non-verbal participants who communicated via AAC tables. Participants who played One Switch Invaders unanimously reported it was the most fun of the games tested, and notably stated they had never played anything similar before. This finding underscores how dramatically limited accessible gaming options have been for children with severe motor disabilities. The research validates that dynamic, time-dependent game mechanics are achievable within one-switch constraints when appropriate interaction paradigms replace traditional scanning.
Relevance
This work addresses a real equity issue in gaming: children with severe motor disabilities deserve access to engaging, dynamic games comparable to what their peers without disabilities enjoy. UNICEF estimates that 5.1% of children worldwide live with moderate to severe disabilities, representing a substantial population underserved by current accessible gaming options. The GNomon framework demonstrates that technical solutions exist to bridge this gap—the barrier has been design assumptions, not fundamental limitations of one-switch input. For accessibility practitioners and game developers, the key insight is that scanning is not the only one-switch interaction paradigm. Alternative approaches like NOMON can enable selection of arbitrarily positioned, moving objects without compromising accessibility. The collaborative design process with clinical professionals (therapists, psychologists) also models good practice for developing assistive technology that meets actual user needs rather than assumed requirements.
Tags: switch access · game accessibility · motor disabilities · children · assistive technology · one-switch interaction · accessible games