Cheaper EEG sensor interfacing for (neuro)feedback would be a major step forward. Using the EEG sensor with various game interfaces is possible, and has been beneficial for patients with Traumatic Brain Injury.
With TBI, the issue is often connectivity between parts of the brain, and that can be measured as EEG Coherence.
I agree with lettergram and others, that without feedback these type braingames don't really do anything.
This is what SenseLabs (https://senselabs.com) are doing with a product called Versus (https://getversus.com). It's an EEG sensor connected to an iPad where you play games.
