Fun to play watch. It has a lot of unexploited potential, in my opinion. Here is an idea: you could make a worm appear wherever the user clicks on the apple. The worm would slowly grow and eat the apple. But why limit it to only one apple? Make an entire tree full of apples, the user has to infect all of them with worms. Every couple seconds another apple grows on the tree, so the user has to be quick...