From the looks of it you seem to be using the Sonic 3 engine. Is this correct?
Yes and the SNES version will be using the SuperFX. In the final there will be a major sprite and art overhaul to make it resemble the Wii/PC version of Sonic 4 more.
EDIT: I fixed the tags.
Currently owned flash carts: EDMD v3, R4i 3DS SDHC, R4i SDHC Gold PRO, R4i 3DS Gold, SD2SNES
Currently owned consoles: Sega Genesis Model 1 x2, 32X, Dreamcast, PS2 Slim x2, PSP, SNES x2, DSi XL, GBA SP, Wii