A Royals game is fairly inexpensive, 7 dollars for tickets, then you could split the parking fee.
There are parks along the river that you could go and walk around in; Parkville, up north of KC, for example, has an excellent park and the town is pretty neat to walk around in, too.
And, as everyone has said, the Plaza and Zona Rosa are also neat to explore.
Here_s the site for your 33 free adventures:
http://kansascity.about.com/b/a/256895.h��
Enjoy!!
Keep going another block east of that, and spend some time at the Nelson-Atkins art museum. They accept donations, but that can be just a buck or two. The Nelson has European and American masterpiece paintings, and examples of ancient and medieval, Asian, and Native American works of art.
Speaking of Native American, if you can travel an hour or so west of KC, drop in on some of the local Indian casinos. You don_t have to gamble, and there_s no cover charge. I would really recommend Harrah_s Prairie Band Casino, about 20 minutes north of Topeka. There_s always something going on there. They have a great buffet, and also a smaller restaurant where you can a buffalo burger 24/7. In fact, that_s another point... the casinos never close. This is also powwow season, and the local tribes will each be sponsoring one over the next couple of months. There_s generally a $7-8 a head charge, but you can easily spend a day at one -- or at least all evening.
Drive north to Atchison, KS (about an hour from KC); visit the Amelia Earhart Home (a small charge), or the train museum (with many authentic train engines and cars that you can walk through). Take the trolley through Atchison for a tour of the local haunted houses (this town has been called _the most haunted town in America_ by the Discovery Channel).
Head over to Cabela_s. Spend some time walking through their aquarium. See the diorama of the African veldt, the wildlife mountain in the middle of the store, and the hall filled with record-breaking deer antlers.
Go to Lawrence, KS and walk up and down Mass Street. This is a shopping and entertainment district for a major university town. Lots to see and do. If you can afford to splurge a little, get lunch at The Mad Greek. Later, work off the Greek food by driving to the public access lookout tower south of town, and climbing to the top. The view is great, and the price is free (except for some huffing and puffing).
Just a few ideas.
zona rosa up north is a fun place to walk around also.
Try this website: www.visitkc.com