Finding what the effect or animation need to be add on

I watched a lot of "The Coding Train" tutorial in YouTube to help me revise the code I learn in year one, discovering that there is a lot of effect I can try on and want to add on. The rotational effect is very fun to construct as it has a lot to do with formula of trigonometric ratios and pendulum system counting. The outcome is not as aesthetic as I imagine, but I am glad that I can solve the mass problem of bugs during the process.