The two games couldn't be more different, yet today they set aside those differences and unite on the Android Marketplace. Both 11 bit studios' tower offense title, Anomaly Warzone Earth, and Sega's latest downloadable addition to its tower of Sonic games, Sonic 4 Episode 1, are available on the Android Marketplace today.

Both games will set you back $3.99, though if your particular device is running Android 4.0 (Ice Cream Sandwich) you may want to hold off on Sonic 4 Episode 1 until Sega's ironed out some bugs. Sorry, one of those bugs is not the physics -- you'll need to wait for Sonic 4 Episode 2 for that.