Fish'n'Steps is an interactive computer game designed to encourage physical activity by linking a player's daily step count to the growth and emotional state of a virtual fish in a fish tank. The game includes social elements, such as competition between teams, to foster both cooperation and competition. In a 14-week study with 19 participants, the game served as a catalyst for promoting exercise and improving attitudes towards physical activity. Although most players' enthusiasm decreased after the first two weeks, analysis using Prochaska's Transtheoretical Model of Behavioral Change showed that individuals had established new routines leading to healthier physical activity patterns. The game combines the ubiquity and simplicity of pedometers with the engagement of social computing games. Participants were provided with pedometers to measure their step count, which was then mapped to the growth and emotional state of their virtual fish. Additional incentives included social dynamics such as team competition. The study found that 14 out of 19 participants experienced positive changes, either in their daily step count or in their TTM levels, or both. The study also highlighted the importance of careful selection of incentives, as unachievable goals can fail to inspire change. The game's design aimed to provide positive reinforcement through the virtual pet and social interaction. However, the study noted that the game was perceived as repetitive over time and that the pedometers were inconvenient for some participants. The study demonstrated that Fish'n'Steps effectively promoted physical activity, with participants showing increased step counts and improved attitudes towards exercise. The game's success was attributed to its ability to engage participants through a fun and interactive approach, while also aligning with the Transtheoretical Model of Behavioral Change. The study also highlighted the importance of considering individual differences in physical activity levels and attitudes when designing interventions. Overall, Fish'n'Steps proved to be an effective tool for encouraging physical activity, particularly for individuals at intermediate stages of behavior change.Fish'n'Steps is an interactive computer game designed to encourage physical activity by linking a player's daily step count to the growth and emotional state of a virtual fish in a fish tank. The game includes social elements, such as competition between teams, to foster both cooperation and competition. In a 14-week study with 19 participants, the game served as a catalyst for promoting exercise and improving attitudes towards physical activity. Although most players' enthusiasm decreased after the first two weeks, analysis using Prochaska's Transtheoretical Model of Behavioral Change showed that individuals had established new routines leading to healthier physical activity patterns. The game combines the ubiquity and simplicity of pedometers with the engagement of social computing games. Participants were provided with pedometers to measure their step count, which was then mapped to the growth and emotional state of their virtual fish. Additional incentives included social dynamics such as team competition. The study found that 14 out of 19 participants experienced positive changes, either in their daily step count or in their TTM levels, or both. The study also highlighted the importance of careful selection of incentives, as unachievable goals can fail to inspire change. The game's design aimed to provide positive reinforcement through the virtual pet and social interaction. However, the study noted that the game was perceived as repetitive over time and that the pedometers were inconvenient for some participants. The study demonstrated that Fish'n'Steps effectively promoted physical activity, with participants showing increased step counts and improved attitudes towards exercise. The game's success was attributed to its ability to engage participants through a fun and interactive approach, while also aligning with the Transtheoretical Model of Behavioral Change. The study also highlighted the importance of considering individual differences in physical activity levels and attitudes when designing interventions. Overall, Fish'n'Steps proved to be an effective tool for encouraging physical activity, particularly for individuals at intermediate stages of behavior change.