Most, if not all, the activities should be easily accessible to wheelchairs. They are mostly at desks or tables. The only thing I am not sure of is the indoor playground area, but there are at least a few things there they could take part in, including a large, lighted peg board (similar to a Lite Brite, but much bigger).
There is plenty of room for wheelchairs. I can think of only one of the activities that a child in a wheelchair wouldn't be able to do.
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