Sideshows like Halloween face painting, fire breathers, pumpkin carving for younger (and older) visitors, find the golden pumpkin and win an annual pass, actors jumping out periodically simulation zombie attacks on other actors disguised as visitors with puddles of fake blood. Oh, they could hire out some small boats, dress them up with lanterns and the like and have 'The Boat Man' take people out on the lake as though he were taking them to hell. I'll come back with some other suggestions.