Have a "swamp" set up with a person behind and inside the decoration. Make "fishing poles" out of twigs and string, with a big plastic "S" shower curtain hook on the end.
When the drop their "line", someone in the back hooks on a spider, skeleton, witch, or any one of the cool things you can get at the local dollar store.
I used to help out with my daughters Fall Carnival, and we let kids guess how many "eyeballs" there were in a jar (make of ping pong balls with magic marker to help make them real) and with slightly tinted red water inside. That was fun.
You could make a "wheel of misfortune" that the kids could spin. Set the outside for the older, going inward to the little ones. For the older, movie coupons, gift cards or coupons for rides to the mall. For the middle, something age appropriate like coloring books and crayons, picture books. For the little ones, who doesn't love teddies! You can get them new at the dollar stores, or used for as little as .50 at the thrift shops.
When my son was young, I helped at the church's fall festival. Some of the games were very simple for the small children...pencils in a bale of hay, some sharpen, most not sharpened, if they selected a sharpened one, they received a prize. That's the only one I can remember.
Have the children dress up as Bible Characters and for a fun game have the kids take turns drawing a picture at a time and allowing the others to guess what Bible story they are referring to such as NOAH...
Draw an Ark/elephant/bird with olive leaf etc. The list goes on. This sounds like a neat party for Halloween. May God bless!
We just came back from our church fall festival. They had a new game. Make a cross from 2x2 wood sticks (vertically about 6 feet and horizontally about 4 feet). attach strings to hang down that you tie mini donuts to. kids sit on bench and have to eat without their hands from the string. first one that finishes swallowing theirs wins.