How to play Gun Force II on Mac

Gun Force was an obscure Contra-like game you might have seen at the arcades back in the day. It was "feed me all your quarters" hard and pretty much unplayable, but contributed one exciting new element: you could jump into war vehicules and used them against the enemy. Most of you probably didn't even know that it had a sequel. Gun Force 2 was one of the last arcade games (if not the last one) from Irem Corp., published in 1994. When looking at the screenshots, the game's similarity to Metal Slug becomes evident immediately. Yes, Metal Slug is an evolution of this game, as the staff members are actually the same. When Irem Corp. ceased activity, a group of its staff members got together and founded Nazca Corp. They revived their last idea, pumping it up and calling it Metal Slug on the Neo Geo system. Gun Force 2 is easier and even more enjoyable than Metal Slug. You won't need a dozen quarters to finish it. It's much friendlier and more replayable, but there's less to see and find through out the whole game, as it's just not as technically complex as its modern brother. Your character is equipped with two guns at the same time that can aim in any direction, at a slightly different angle each. Different weapons are available but only one of your guns can be upgraded, with the other one always keeping the basic shot. There aren't any bombs or grenades, though. Our hero can jump, crouch and hang from ceilings and wires, and also use one of eleven (yes, eleven) war vehicules. This is why Gun Force 2 is so cool. Engaging the enemy with bipedal walkers, jeeps, tanks, and even a Gundam-like flying suit provides such a fuzzy and trigger-happy feeling. Your objective in every level is to rescue hostages for higher scores, which was also later taken over by Metal Slug. Luckily, they are sexy half-dressed cuties instead of Robinson Crusoe's look-a-likes, but they won't leave any rewards or power-ups behind. Plot-wise, Metal Slug and Gun Force are not related, althou