How to play Global Defence Force on Mac

The second game in the The Chikyuu Boueigun series, renamed Global Defence Force for its English release (similarly the first game was renamed Monster Attack for its English release). It's been two years since the invading alien menace was defeated by the Global Defence Force (the game renames the "Earth Defence Force" from the previous game), but like any good off-world threat, they're back for more, and they've brought new weapons and technology in their attempts to take Earth and eliminate humanity. Thankfully, the GDF has also been developing new technology to fight them. Global Defence Force is a third-person action shooter. Choose from either an GDF infantryman or the flight-capable Pale Wing, each with different abilities and dozens of weapons each, and set out to shoot down hordes of giant insects, enormous robots, and UFOs of incredible scale. You can choose two weapons to carry for each mission, and pickups dropped by enemies will unlock new weapons and increase your character's maximum health. You can play the game split-screen cooperatively. Beyond adding a second player class to choose from; the Pale Wing; a fragile but powerful melee centric character with a limited Jetpack and her own weapon set, to go alongside the infantry man of the first game, Global Defence Force doesn't change much of the basic game play of Monster Attack. But leaving at that would undersell the game; there are numerous new alien types, weapons and environments that add much more variety to things. The maps are larger and more detailed and missions are longer and much more scripted (where as the original game nearly always threw you into an environment against some preplaced bug's, this time you often have some simple objective(s)) to add further variety. Finally the physics have been notably enhanced. Like Monster Attack, the player in Global Defence Force fights completely by themselves despite being part of an army (unless playing offline only 2 player split screen); the