Neil Peirce finds that;

“Although there is a limited amount of academic research in this area, there is evidence of the benefits of specifically designed games, notably in the areas of phonological awareness, differentiating relationships, memory enhancement, coordinated motor skills, and mathematical development. However, these benefits have only been evaluated over several months in a structured preschool environment. The impact of such games being played intermittently in an informal setting is an area of
open research.”

Download a copy of the report here [PDF].