O.zen like the dragons, I guess it's still coming

I recently came across a technical report evaluating the O.zen, a biofeedback game being developed by Ubisoft. Having followed the game since its announcement in 2010, I’m kind of underwhelmed by the contents of the report.

The report describes a preliminary study of O.zen’s ability to reduce stress through controlled breathing exercises. This is a common biofeedback training exercise also known as heartbeat rate variability (HRV) based biofeedback, given the user’s breathing is measured indirectly through their heartbeat. The study compares a group of people playing O.zen against a control group who watch videos of O.zen being played who in addition engage in a cognitive task (i.e. counting).  The study uses a mixture of physiological (e.g. skin conductance) and psychological measures (e.g. state-anxiety test) to evaluate the efficacy of O.zen in reducing stress.
Sadly there’s nothing much here to write about. While I appreciate the comprehensive analysis it feels unwarranted for a preliminary study. The efficacy of O.zen is being evaluated using a small population group (N=28), for a single thirty minute training session, against a somewhat dubious control (the control group should not have been assigned a cognitive task — I don’t see a justification for it). Both groups saw a reduction in measures of stress over the course of the study but you’d see that of anyone sitting down for a while. The report did raise some interesting topics concerning how visual aesthetics might improve biofeedback training (a topic I’m interested in myself), but the study doesn’t tackle it here and the conjectures about the impact of O.zen’s  aesthetics on stress need to be validated against a suitable control (e.g. compare a gray-scale O.zen against the colour version).
I guess my chief gripe with this report is that it’s been 5 years since what appeared to be a largely completed product was announced and all there is to show for it is your bog standard proof-of-concept technical system evaluation. This study doesn’t really show O.zen is any more capable of stress reduction than anything else.  A better study would of investigated its longitudinal impact on stress measures or perhaps how its visual aesthetics improve upon existing biofeedback paradigms but I don’t have my hopes up we’ll see such reports.
As of right now O.zen is still in development, and like the dragons I guess its coming.

Report: Ana Julia Moreira, Laurent Sparrow, Yann Coello, Odile Viltart, Sabrina Hassaini, et al.. Does playing O.zen improve our well-being?. [Research Report] SCALab UMR 9193, Universite de Lille. 2015. <hal-01129626>