Use Dr. Eggman's attacks against him.
— Description, Sonic Runners
The Saw Arm 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 shoot out sawblades attached to a yellow or black orb either vertically or horizontally.
The player can Spin Jumping into the sawblades' orb for different effects, although it requires precision since the characters can easily hit the sawblades. Hitting the black orbs will destroy them and their sawblades while hitting the yellow orbs will knock them and their sawblades back at Eggman. The latter is the player's only means of damaging the Eggmobile. Keep hitting knocking yellow orbs 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 Saw Arm Eggmobile will increase in Health Points from five and up to twenty, while its battles get faster and more difficult.