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.
i understand what your thinking was, but i just wanted to point out that middle school kids are who TMNT was made for. They would be their core demographic, meaning that this particular middle school kid maybe is a SUPER TMNT fan. so saying that, i think its totally plausible that a middle school kid got it in his head that if he poured green goo (probably some antifreeze found in his parents garage) over his pet turtles they might turn into mutants. he definitely wouldnt win any awards in the science fair, but i feel its conceivable in the context of this derby that a kid might try it.
the joke here is that the kid thought it would work, but since this is the real world and not a cartoon, the turtles die. i think that is completely something that could happen.