In BrainWave Visualizer, why do my high scores in the ball-floating game and barrel-burning game reset to zero when I leave the game? How do I keep my high scores between sessions?

The two games in Brainwave Visualizer are really intended more as technology demonstration mini-games, rather than full-fledged games. As such, the “high scores” (float height, and burn time) are only there for amusement, rather than true “high scores” as in typical games. A future revision of Brainwave Visualizer may keep the scores between sessions. For now, use them to just challenge yourself during each session that you play.