It has been a bittersweet couple of months for fans of iOS shoot-em-ups. The removal of 32-bit support in the latest version of iOS effectively took out a swath of stunning games in one fell swoop, most notably the entire library of amazing arcade ports of Cave's games. On the positive side, the latest in the Danmaku Unlimited series released, and it was every bit as incredible as we could have hoped. Well, we can chalk another one up for the angels with the international release of Aka to Blue [$7.99], a brand-new bullet hell ballet from Tanoshimasu, a small developer founded by ex-Cave staff. The team's pedigree shows. This game could easily slide into Cave's line-up without much effort, even if it's not quite as rich in extras as some of their mobile ports. You can take your choice of two fighters, Aka and Blue, through five stages of vertically-scrolling shoot-em-up action. The bullets fly hot and heavy, and the only way you'll survive is by mastering the game's main hook: its bomb mechanics. Unlike most Cave shoot-em-ups, bombs aren't discrete items to pick up and use in Aka to Blue. Instead, you'll charge them up through a variety of methods, with each level bringing a longer-range, bigger blast that erases bullets and sends score items pouring out of the enemies. Since one of the ways you can charge up your bomb is by destroying enemies and absorbing their shots, careful use of the bomb can give you a near-perpetual supply for great stretches of the game. Even a leve...