A game performing method for making a computer device execute a predetermined game by generating a first object and a second object as seen from a virtual camera, has: judging whether there is a hit between the first object and the second object; judging whether a predetermined event occurrence condition is satisfied if it is judged that there is the hit between the first object and the second object; generating a first image which is an internal structure object of the second object if it is judged that the predetermined event occurrence condition is satisfied; and generating a second image which is the internal structure object with a predetermined part thereof changed after the first image is generated.