At first look, the fact that this game even works inspires some incredulity. What’s promised by the Mindflex Duel is a battle of wills – the clean looking, white and blue board game features two headsets that claim to use EEG technology to scan brainwaves. Each player’s ball rises or sinks on the board according to their respective concentration levels. So, there it is. A game where you actually use your mind, and nothing else, to compete.