Well there is so much more to Central PA than Hershey. Gettysburg is another great place. Not too much farther is Baltimore inner harbor and one of my all time favorites is Harpers Ferry.
Even Harrisburg has a lot and the Army Heritage Museum right next to Carlisle, still have not been there. Old train rides for the family, etc. Lots to do. Hershey Park itself to me is a rip-off now.