Table 1.

Responses to the usability statements (derived from the System Usability Scale [51] and Net Promoter Score [52]).

Item number	Statement	μ (95% CI)	σ
1	The game was easy to use.	3.87 (3.32-4.42)	1.03
2	It was easy to understand how the game worked.	3.56 (2.89-4.23)	1.26
3	The game was too complicated.	1.75 (1.29-2.21)	0.86
4	I can recommend the game to others.	2.37 (1.65-3.09)	1.36
5	I am satisfied with the game as a whole.	3.31 (2.77-3.85)	1.01
6	The game was difficult to use.	1.94 (1.23-2.65)	1.34
7	I think I need someone’s help to use the game.	1.75 (1.22-2.28)	1.00
8	I think most people would learn to use the game quickly.	3.69 (3.08-4.3)	1.14
9	It was hard to learn to play the game.	1.69 (1.11-2.27)	1.08
10	I would like to play the game again.	2.56 (1.76-3.36)	1.50
11	The game was too troublesome to use.	2.37 (1.57-3.17)	1.50