SRB2 TGF (or SRB2 The Games Factory) was the first version of SRB2, which was developed between March and July 1998 before being scrapped. Unlike all following versions, SRB2 TGF was still a 2D game, created with the game-making tool The Games Factory. Compared to Sonic Robo Blast, SRB2 TGF was considerably more advanced: It featured monitors, springs, shields, spikes and the ability to spin on the ground. The levels included features such as water, moving platforms and mine carts. Enemy collision was much less buggy and the player could now bounce off enemies and monitors. SRB2 TGF was later scrapped to be released as the 3D game in the Doom Engine.

Months after Dr. Eggman's defeat in Sonic Robo Blast, the mad doctor took an interest in harnessing energy from a mysterious asteroid that hovers over the planet once every five years. After claiming it as his own battleship, Eggman chose Greenflower Mountain as his first target for obliteration. Sonic was enjoying a long overdue vacation when he was suddenly alerted by the presence of Eggman's massive fleet. Sonic gazed at the giant battleship aimed toward the mountain , and had already bolted towards it in a blink of an eye. Even though Sonic rushed to save Greenflower Mountain as quickly as possible, it had already been destroyed in by the time he arrived. Now, after a quick reunion with the evil doctor, Sonic and friends journey off onto another quest to save the world from Dr. Eggman.