SlashGear: Brain-monitoring mental agility game Mindflex has spawned a new version, Mindflex Dual, and as the name suggests it allows two players to go head to head and see who has the most powerful brain. Expected to ship on August 15, Mindflex Duel uses the same “mind-eye” concentration headbands as the original Mattel game, but allows you to battle it out against an opponents mental skills.