Use Dr. Eggman's attacks against him.
— Description, Sonic Runners
The Iron Ball Eggmobile is a recurring boss in Sonic Runners which can be fought with any character in the game at various points in the game.
During the battle, the player automatically chases after Dr. Eggman in his Eggmobile. However, the Eggmobile always stays out of the player's reach, meaning it cannot be attacked head-on. As his offensive against the player, Eggman will drop iron balls or yellow balls that bounce towards the player at varying heights.
By Spin Jumping into the yellow balls, the player can knock them back at the Eggmobile and damage it. Keep hitting knocking yellowing balls back at Eggman until he runs out of hit points. Eggman will then retreat and the player will have cleared this boss.
As the player progresses through the Episodes of Sonic Runners, the Iron Ball Eggmobile will increase in Health Points from five and up to twenty, while its battles get faster and more difficult.