Studies have identified various challenges and disruptions young adults experience when faced with cancer beyond the physical risks associated with the disease. These disruptions have the potential to trigger a wide range of negative emotions, such as being overwhelmed, anger, fear and worry, sadness, depression, and loneliness. Unfortunately, many of these difficult emotions are accidentally triggered during everyday interactions with individuals who may not be aware of the challenges cancer brings. The purpose of this paper is to describe the development, reception, and effectiveness of the minigame Know Me Better, a mobile serious game based on the first author’s experience as a young adult (YA) cancer patient. The game is designed to raise awareness of the many difficulties and feelings that YA cancer patients could encounter to help their friends and family engage in healthier and more productive conversations and avoid toxic positivity. To assess the game’s effectiveness, we conducted a user study with 18 participants, utilizing qualitative pre- and post-questionnaires to collect their feedback. The findings showed that participants acquired meaningful knowledge, developed empathy for the main character, and expressed a keen interest in learning about additional challenges, paving the way for future studies.