"We understand that you can't wait to play the game but we were not 100 percent sure that the experience would be perfect on all Android devices. That's why we have taken the decision to take one more week to fully optimize the game for all Android devices, even the less common ones."
Rayman Jungle Run launched on iOS yesterday, though it and the Android version were both scheduled to launch today. The iOS version is $3 on the App Store.
Rayman Jungle Run is an auto-running platformer built for touchscreen devices, tapping to jump and holding to hover. Think Canabalt mechanics with Rayman art. Then say, "Oh, yeah."