Preference for competitive or cooperative games?
Totally depends on the goals and audience. I have wrriten a fair amount on this topic previously, including for some specific populations (see References section).
With some populations some competitive games can be devastating to their self-confidence if they lose (ASD and others), while others, with proper guided processing, can get some real benefits win or lose (often most benefit from losing and then helping them process what they can learn).
Personally I prefer cooperative games because of the amazing things breaking out of so many rigid thought patterns that can be accomplished, when switching from zero-sum thinking to non-zero-sum.
References
ADD/ADHD Classroom Modifications: Gamification - Competitive vs. Cooperative
1994 - Cooperative games: a way to modify aggressive and cooperative behaviors in young children
An Overview History and Potential Therapeutic Value of Role Playing Gaming
Potential Benefits and Deficit of Role Playing Gaming
Therapy is fantasy: role-playing, healing, and the construction of symbolic order.