What Counts As A "Church"?

RLUIPA Defense blog last week recounted the story of Spokane, Washington's "Jedi Alliance" which bills itself as a church.  Tim and Tyler Arnold purchased a large collection of arcade games. Looking for a place to house them permanently, they purchased a building that formerly was used as a Methodist church.  Then, however, city officials told them that the building was zoned only for residential use or use as church.  So the Arnolds registered as a church, opening the building on Sunday evenings for the public to play the arcade games or patronize the gift shop.  The Arnold brothers said:

Is it a church? Well, it’s a church in the sense that we took over a church building.  Are we here congregating? Yes, we’re here congregating getting together.  We can use all of this pop culture stuff to bring people together, to get people to have a reason to come together in a social setting.