The problem with apps is that most sacrifice substance for style. Flawed mechanics and flat gameplay are easily forgiven when you touch the screen and make beautiful things happen. Helsing's Fire is the first iPhone game from Ratloop, and its stylish exterior makes it an easy sell. But Ratloop, the developer behind the excellent indie Rocketbirds: Revolution!, aims to fill that shell with strategic depth and a genuinely interesting mechanic. In the end, though, Helsing's Fire still leans more heavily on being attractive.