How to play Transball on Mac

In the distant future the sun around your planet has died off... The only energy source are the "energy spheres". Each of these spheres contains enough energy for a planet to survive for a whole decade, since they are charged with the energy of other stars. An opportunist civilization has stolen all the charged spheres from your home planet, preparing for a future invasion. As a last chance, the last remaining sources of energy have been transfered to a scout ship and sent to recover the spheres... this is your last chance of survival! In each level of Transball, the goal is to find the energy sphere, capture it and carry it to the upper part of the level. The main obstacle is the gravity, that pulls you towards the ground. But many other obstacles such as canons, tanks, doors, etc. will make your journey harder than it seems.