I have a story about that place from the 70s... I'm sure things have changed, but I nor anyone in my family will ever return.
So, we drove from Belleville, IL down to SDC for a family vacation in the summer, much like you plan to do.
My best recollection of the place is three fold. It was my mom, dad, sister, dad's parents, and I.
1. 1st issue upon entering... This creepy clown that was running around threatening to give people shots with a fake needle. It came to the point that my dad grabbed the dude and told him he was going to beat his ass if he didn't leave. My sister was bawling in fear. I think she was 4-5 at the time.
2. Mule ride. Grandpa actually knocked out a mule I was riding when the mule stepped on his foot, refused to move, and the mule handler was laughing.
So, that got us thrown out, which by that point, I thought the place was a shit hole (I was around 9) and was happy to go.
3. The final straw that threw dad over the deep end. Got out to the car, which was a 71 GTO, black on black. They put a f'n SDC bumper sticker on every car in the parking lot. Dad had paid a body shop to strip and paint the rear chrome bumper black, which is where they put the sticker. Had they put it on the back glass, probably wouldn't have been a big deal. By the time the cops were called and the whole thing was over, we got our money back, and they paid to have the bumper painted again.
So yeah, your mileage there may vary. Good luck.