Welcome to this week’s edition of iOS Gems! This week, we look at three recent releases that attempt to capture the magic of classic arcade games: one is a sequel to a very long-running series of arcade shoot-em-ups, the next is a member of a less well-established shooter franchise, and the last aggregates a bunch of classic pinball machines within a single app. Our top pick of the bunch is Pinball Arcade, though shooter fans may also want to…