And all of the other derby entries are experiments where you went to school? Kissing frogs? Pouring the sky out of a jar? Using a blender to blend birds for colors? Plants with tongues? Mutation/radioactivity/poisoning to create the Hulk? Testing magnets on chicks? etc. etc. etc.
Sky in a jar is a real middle school level experiment.
Blending birds, while not a real experiment (hopefully), is an experiment based on the color spectrum, which is middle school level science.
The plants with tongues entry is framed around a common middle school plant growth experiment, presumably gone awry. But there's no indication that the purpose of the experiment was something beyond a middle school science level.
The "Hulk" kid seems to be working on some kind of generic chemistry experiment and nothing suggests that it's past a middle school level of expertise.
Whatever the hypothesis the girl kissing frogs has, it's not above a middle school level and she's clearly at a science fair trying to prove it.
All of those can be seen as middle school level science, whether real or imaginary, while purposefully researching animal mutation via radioactive material is not. Per the derby rules: Keep it at a level you would expect walking into a grade school gym to judge a kid's experiment. Radioactivity's effects on animal mutation, which is what this experiment appears to be about, is not at that level. Hope this helps explain.