Ok. There are three golf courses. Also, they have recently opened a paddle boat that offers rides up the Mississippi about three times a day. All of the casinos have pools and good buffets which you can go to without being 21.
I'm afraid that's about all there is to do in Tunica, but you could drive up to Memphis and there are a lot of sights to see up there. Like I said, its about 20+/- miles north on a 4-laned road.
Hope this helps some.