@Damnitspongebobby As a re-creation of the classic games, perhaps. But it's not just that, it's a game in its own right (sort of—the episodic release was a mistake), and quite a few of its levels would have added something to the classic games.
They saw fit to put the first two parts out there, so they should have finished what they started. I heard there were supposed to be four episodes in total, so I bet Episode 3 would have been based on Sonic CD and had Amy while Episode 4 would have been based on Sonic 3 and had Knuckles.