Radioactive Rabbit vs Feynman rules

Help Ricky the radioactive rabbit escape the dastardly clutches of the Nuclear Waste Management Service. After undergoing generally unpleasant tests involving unspeakable things with uranium rods, Ricky has finally made a break. A long time coming, by the dark of night he has escaped, but a glowing pink rabbit is hard to miss and the waste management goons are in pursuit - you must hop your way through pools of ooze, nuclear mines and ghastly green goop to reach freedom. Ricky needs to eat radioactive goodies to fuel up his super hopping power. Make sure he avoids any green nuclear waste products and keep him moving to stay one step ahead of the cleanup squad chasing him in the van. Pick up carrot bonuses to unleash Ricky's crazy mutant powers, warning, safety glasses not included!

This app introduces Feynman rules. You can get some understanding for Feynman diagrams. E is external point, V is vertex, P is propagator, and S is symmetry factor.