Creative prompt.

If you're going to get the seniors into the place, the first thing you have to do is make an Early Bird Special. Sure, you're starting everything at noon but you have to reward the folks who get their butts in the seats early because seniors love a good deal. So those who show up before 11am get a voucher for $2 off any one item at the concession stand. Only two dollars? Look, seniors just want a good deal, it doesn't have to be a great deal. And if you gave them a coupon for dinner after the game? Even better. Partner with a local Chinese restaurant or something, preferably some place that has their own Early Bird Special. Then upon leaving, give folks the coupon for 10% off this restaurant. Just make sure that the restaurant can handle the influx of people because all those seniors are definitely going to be trying to get that deal (that is, if they're anything like the folks who live in the South Florida retirement community where my grandparents reside). More than anything in this world, seniors love good deals. Other than that, maybe have an associated Mahjong tournament or something; I know my grandmother is pretty into playing that with her friends.