How to play Varth: Operation Thunderstorm on Mac

Varth follows the story of a disaster that befalls a human colony on a planet of the same name. The entire colony is run by a 7th generation supercomputer which controls the operations of all machinery on the planet. Unfortunately for the residents of Varth, Delta-7 has been possessed by the entity "DUO" (Dimension Unbody Offender), thought of as an evil spirit but actually a temporal-spatial consciousness which spontaneously arose within the supercomputer. DUO has come to the conclusion that human existence is inimical to the planet, and has therefore turned the planet's defenses against its own populace. Eighty percent of the planet is laid waste by the event, and this is only the beginning of DUO's cleansing scheme. The colonists' reliance on the supercomputer has caused them to lose the ability to take care of themselves, and thus have no means of fighting back. The only hope for the colony lies in the pilots of two planes equipped with 4th generation computers which DUO cannot control—they are controlled not by machinery, but by humans.