Sonic 2, one of the first Sega games many children played as a kid. Also one of the newest games released as part of Sega Forever. But does it hold up on a cell phone? Like most of the Sega Forever games it really does. The sound is easily equal or better than its original release, and the controls translate quite well to a touch screen.
The only real issue is for most people there are better options out there for the Sonic games. Most of them can be purchased on the Xbox One or the PS3 and XB360 consoles. They work well on a phone but there really is no reason to play on one if you own one of those systems. Best wishes and may the gaming gods bring you glory.