Traditional games like "Tag" rely on shared control via inter-body interactions (IBIs) – touching, pushing, and pulling – that foster emotional and social connection. Digital games largely limit IBIs, with players using their bodies as input to control virtual avatars instead. Our “Shared Bodily Fusion” approach addresses this by fusing players’ bodies through a mediating computer, creating a shared input and output system. We demonstrate this approach with "Hidden Touch", a game where a novel social electrical muscle stimulation system transforms touch (input) into muscle actuations (output), facilitating IBIs. Through a study (n=27), we identified three player experience themes. Informed by these findings and our design process, we mapped their trajectories across our three experiential spaces – threshold, tolerance, and precision – which collectively form our design framework. This framework facilitates the creation of future digital games where IBIs are intrinsic, ultimately promoting the many benefits of social play.

Experts emphasise that maintaining a healthy gut microbial balance requires the public to understand factors beyond diet, such as physical activity, lifestyle, and other real-world influences. Games as experiential systems are known to foster playful engagement and reflection. We propose a novel approach to promoting activity engagement for gut health and its reflection through the design of the Go-Go Biome game. The game simulates the interplay between friendly and unfriendly gut microbes, encouraging real-world activity engagement for gut-microbial balance through interactive visuals, unstructured play mechanics, and reflective design principles. A field study with 14 participants revealed that important facets of our game design led to awareness, playful visualisation, and reflection on factors influencing gut health. Our findings suggest four design lenses– bio-temporality, visceral conversations, wellness comparison, and inner discovery, to aid future playful design explorations to foster gut health engagement and reflection.

The size and cost of electroencephalography (EEG) headsets have been decreasing at a steadfast pace. Prefrontal cortical activity is a promising input source that is also important for affect regulation. We created Joie, a joy-based EEG brain-computer interface (BCI) which uses prefrontal asymmetries associated with joyful thoughts as input to an endless runner game where the user’s character collects coins in response. In a lab study (20 participants, 15 training sessions per participant, up to two weeks of training), we found that our experiment group instructed to imagine positive music, winning awards, and similar strategies, demonstrated significantly greater ability in activating asymmetry compared to our placebo and control groups. In our analysis, Joie demonstrates the ability for prefrontal asymmetries to be used as input to an affective BCI and builds upon prior work in this area. Training these asymmetries can teach mental strategies that have applications in mental health.

Spectating digital games can be exciting. However, due to its vicarious nature, spectators often wish to engage in the gameplay beyond just watching and cheering. To blur the boundaries between spectators and players, we propose a novel approach called "Fused Spectatorship", where spectators watch their hands play games by loaning bodily control to a computational Electrical Muscle Stimulation (EMS) system. To showcase this concept, we designed three games where spectators loan control over both their hands to the EMS system and watch them play these competitive and collaborative games. A study with 12 participants suggested that participants could not distinguish if they were watching their hands play, or if they were playing the games themselves. We used our results to articulate four spectator experience themes and four fused spectator types, the behaviours they elicited and offer one design consideration to support each of these behaviours. We also discuss the ethical design considerations of our approach to help game designers create future fused spectatorship experiences.