The second of the two known bosses is Metal Sonic who, just like Fang, is enormous.

As well as fighting Metal Sonic, you also have to avoid being hit by big spikey blobs.

Unlike the other screenshots, this one has a city in the background. This could mean one of two things:

1. It's a different version of the game, but is essentially the same level.
2. It's a different level, and you in fact have to fight Metal Sonic twice.