Skittles. M&Ms, Bottlecaps, sweettarts, valentine hearts, smarties, etc)
Design a game, or series of games around the idea that all the customer gets is the game board. They supply the game pieces.
Each game would be geared toward a different candy and take advantage of the candy colors, shapes, flavors within the rules.
A key selling point (beyond getting to eat the pieces during and after the game) is that unlike most games, it's easy to find replacement game pieces.