Chromanoids is Hothead Games' second title for the App Store. The first was Bunny the Zombie Slayer, and it's done pretty well (even though most of the studio's previous work was for PC). This one's a more retro affair -- it's basically Missile Command, though obviously with the touchscreen rather than the traditional wheel. But the twist here is that the action is color based -- you need to not only line up shots against invading ships, but you need to match shot colors with ship colors, which means red ammo takes down red ships, and so on.
Things do get more complex as the game moves on, with ships that use colored shields and even ships that change color as they fly