Champion of Breakfast
Much is described in dialogue, so literal representations of a giant bowl, toaster or microwave oven aren't necessary. Non-descript objects can be used to suggest these items - for instance, a regular door can be used to represent the door to the microwave oven. The audience doesn't see the inner workings, they only hear things slamming against walls as food inside splatters.
A door for the microwave oven
Something to represent a giant bowl, twice
Something to represent a giant toaster
Something to represent a pot of scalding water
Something to represent a container of sour skim milk
Something to represent a container of honey
Something to represent a container of cinammon
Something to represent gobs of butter
Something to represent a large knife
Similarly, the costumes need not be elaborate. The actor playing the breakfast contestants can simply be dressed in a T-shirt on which different names (Bread, Cold Cereal, Hot Cereal, Egg, etc.) can be attached and removed quickly, for instance with velcro. For the Mystery Guest, the addition of a mask and cape would be welcome. The Announcer for the game show can be as plain or garish as the designer sees fit.
Cast of Characters
malicious host of the game show, "Champion of Breakfast" - may also be played by a young actor, if they so desire (making the adult the multiple contestants instead)
SLICE OF BREAD / COLD CEREAL / HOT CEREAL / EGG / MYSTERY GUEST
The various contestants in the game show, vying for the title of "Champion of Breakfast" - some more successfully than others - these contestants may also be played by an older actor (if the youth and adult actor chose to switch places)