Cortex + Challenge tests up to 2-6 players’ memory, cognition, and sensory perception. It even includes texture cards that are used during "touch challenges" in which players must guess what they are feeling, adding a unique element that is often neglected in games. Winning challenges allows players to add pieces to their brain 3D puzzle which they must complete before their opponents in order to win the game. This game contains 170 new cards, including 9 new challenges and can be mixed with cortex 1, cortex 2, and/ cortex 3