The answer, it turns out, is this cartridge. It's a Sonic game in the broadest sense. Beyond that, the relationship with official Sonic physics becomes strained. Sonic has two speeds — walk and run — and his Spin Dash works only some of the time. His jumping spin attack requires landing directly on top of enemies rather than hitting them from the side. Custom cartridge, plug and play. Compatible: GBC, GBA, GBA SP.
