Table 2.

Design Principles Used in “The Heart Game”

Design principle	Implementation	The experiences of the patients
Daily challenges	Daily revealing of next challenges	The challenges were completed every day by all 10 patients.
Leaderboard	Ranking of teams by points	Nine out of the 10 patients reported being motivated by this.
Points	Points given for selecting and completing challenges	Placement was more important than points, and maximum possible points were used by patients to measure performance.
Achievements	Medals for specific goals	Too hidden in the user interface. Three out of the 10 patients wanted to collect all medals.
Surprise mechanic	New challenges every day	All 10 patients expressed motivation by this feature, and 1 patient stated “It is like an Advent calendar.”
Including the spouse/family member	Spouse as teammate	Nine out of the 10 patients expressed that it helped them to complete tasks and that there being two persons encouraged them.
Variation	Different types of challenges	Eight of the 10 patients liked the challenges, and 2 of the 10 asked for more challenges.
Meaning	Relevant rehabilitation tasks	The tasks were not just seen as a game and had value for their rehabilitation and helping them return to everyday life.
Collective goal	Patients compete against each other.	Promoted completion and social networking among the patients

Patients include the two teams that stopped after 10 days.