Eggman in Sonic Forces is a boss fight that Classic Sonic faces. The design is very reminisce to the original Egg Mobile-H from Sonic the Hedgehog (1991), and so is the general spot the fight takes place in. The only added/changed detail is that the checkered ball is replaced with a deadly spinning buzz saw.
The battle takes place on similar wide arena with two platforms, where Eggman flies down with his Egg Mobile and releases the saw blade from the mobile. It then starts do normal swinging pattern back and forth. The player can easily hit the Egg Mobile from one of two platforms, while watching for the swinging saw blade.
After five hits, Eggman will summon the Egg Dragoon.