Maybe just 1 new game pertaining to that unit; you could make an easier and more challenging version for differentiation. You could also have the students make it fit their needs; they may come up with more ideas! Or have the easier version repeat concepts previously taught and the challenge be a combination of concepts. I hope this helps!

I have just begun using the board this year. I leave some games up all year because those concepts (addition and subtraction) can be practiced throughout every unit. Then I will try to look at what I am teaching to find one or two games that compliment it. Because I am using binders for my games, which are in page protectors, when I take games out, I am filing them under the topic I introduced them so I will be able to add them quickly next year.