Serious games bring gaming beyond entertainment and can be used to teach players about real-life situations. In this thesis, we present a user study with Embrace , a serious game that re-enacts real-life situations faced by cancer patients and show players how decision making can impact the daily life of people who are living with cancer. We shaped the game scenarios of Embrace on the basis of knowledge from two consultant experts who worked with cancer patients for several years. In their work, our consultants identified particular daily life situations (e.g., having lunch in bed vs having lunch with familiars in the living room), where cancer patients struggle with decision-making and where decisions can influence their physical and mental well-being either negatively or positively. We used Embrace in an online user study, where 30 participants played one level of the game that simulated the real-life situations faced by cancer patients described above, and had to make decisions that balance the game character general well-being (i.e., energy and mood). We carried out the user study to investigate the following: (1) if players empathized with the game character and felt responsible for their health and well-being, (2) which decisions participants made and what decision patterns emerged from the gameplay, and (3) the extent to which participants found it hard to make decisions in the scenarios proposed by Embrace. Results from our study show that (1) participants felt responsible and empathized with the game character, (2) participants found easy to make decisions but also needed to think carefully about them, and (3) participants started the game with more conservative choices (e.g., eating breakfast in bed), but moved towards more prosocial choices by the end of the game (e.g., having dinner with the family). Finally, we conclude by discussing how our results can help the design of health-related serious games and outline directions for future work.