How to play Magical Kid's Doropie on Mac

The year is 1999. When the Akudama Empire attacks the Earth with his army of robots. No conventional weapon in existence is efficient against this opponent. The robots are, however, totally vulnerable to magic. An hired mercenary, Kagemaru, summons the only non-sealed witch, Doropie, to stop the Akudama Empire's offence. The imperial army, led by an old nemesis of Doropie, Empress Elysia, does not surrender though. Elysia captures Kagemaru and blackmails Doropie into breaking her seal and setting her free. It seems that the mercenary lost his life, and Doropie sets out to stop the now-free Empress. After the battle, the dying Empress Elysia confesses the reasons behind the invasion and apologizes. The imperial warship explodes shortly thereafter, but not before Doropie escapes it. She is contacted by Kagemaru, who apparently has survived the wounds that Elysia inflicted on him. Doropie comes back to Earth shortly afterwards.