I would love to be able to stand by a waterfall, perhaps with a wishing pool at its base where we could toss tokens in , throwing a token would give a pop up menu allowing you to imput a wish. very rarely a wish might be granted. Standing near the waterfall would boost your mood and/ or give a small buff that allows mood gain. Perhaps there could be fish in the pool and /or frogs with stepping stones to allow you to cross the wishing pool, maybe they could be slippy so you dont always make it across.
Oh and the frogs could be musical so that hopping on their stones would cause them to croak, so you could play a tune like a floor piano. It could even be adapted to a simon says idea where you have to copy the tune with an achievement if you reach certain levels.