Endless runners are one of the most-used genres on the App Store lately -- from the original Canabalt to later hits such as Jetpack Joyride and one of my current favorites, God of Blades. There are plenty of them out there, and the best ones have some innovation or a new twist. Polara, one of the latest entries to the genre, has both. Not only does it feature a color-changing twist, but the way the game is structured (in a series of checkpointed, story-based missions) puts a fairly new spin on the way these games work.
Polara is an endless 2D runner, in that you play a character that runs along in 2D space, leaping over and through various obstacles. The twist here is that while touching the right side of the screen makes your character jump, hitting the left side makes you switch between red and blue. Then, there are red and blue obstacles to either hit or avoid, and only switching to the right color will let you survive and move on (similar to the treasure shooter Ikaruga).
At first, the game is simple -- just asking you to flip back and forth every so often. But very quickly, it requires you to switch between moving targets and sometimes asks you to match up with alternately-colored platforms. Things can get fiendishly difficult right away.
Fortunately, in the core story mode (decorated with some excellent art and atmospheric music), the game uses checkpoints wisely, so sections are nice and short, letting you easily replay any tough parts. In the other modes, the game is endless, so you've got to be really fast to keep going.
Polara offers up some nice new elements to this well-traveled genre. It's not quite perfect, and it doesn't have the polish of a game like Jetpack Joyride, but it does pull off some really new and interesting things. At the current launch price of 99 cents, it's well worth a download.