This is how to beat the first boss of Sonic 2

Eggman will fly in on his helicopter and attach to a Drill Car. This boss is very simple as Sonic must hit Eggman as he slowly goes across the screen to hit Sonic. Once he has been hit seven times the drill will launch of the car to try to hit Sonic if Sonic avoids this and hits Eggman one more time he wins.
Sonic 2boss1