I got another Football game that looks just like these 2, except it only says Football Electronic Game, without any company name. The model # on the back is the same 003201. But this one has a PIC1655 instead of a TMS1000.
I also got Mattel Soccer, which has an NSC MM4799 like Mattel Basketball- in fact, the PCBs are identical.
And Mattel Computer Chess, which has an NSC SC/MP. I haven't messed with one of these before, but I've read about them on Paul Robson's blog.