Here is a little game I put together in 4 hours of reviewing blendercookie BGE and other tutorials and about 6 hours of playing around in blender. This game is about flying around with butterfly. To get butterfly to get up from the ground you must concentrate enough.
I used Neurosky Mindwave set to get concentration value and tcp client in blender to get this value to BGE. Rest was just finding bugs after glitches and getting right values to physics.
Here is a little video of the game in action.
I think I will continue this project for a while and post more updates I there is interest in this.