Sonic Team, the main developer of Sonic games, has announced Sonic Runners as a free-to-play mobile game featuring 2D side-scrolling stages.
While the announcement video, which you can see below, does not show us any gameplay footage, the image at the top of this post gives us some idea of how it will look.
Japanese magazine Famitsu says the game can be played with one hand as Sonic moves forward on his own and you can tap the touchscreen to make him jump. As with most mobile titles, the game has been designed to be played in short chunks, with stages lasting one or two minutes.
The official Sonic Runners website states that "premium items" will available, likely meaning in-app purchases. An iPhone 4s/5/5s/5c/6, iPod touch (5th-gen or later), iPad 2 or later, or Android OS 2.3 or later will be needed to play.