Hi, under the game jam time constraints there was only so much we could fit into - we felt that 3 different characters were good enough. I agree with the fact that one enemy may not have been enough. As for the coin in the middle of the sky, if you were to read the game's description, help screen, and perhaps some of the helpful commenters on our page, you're supposed to use Q/E to rotate the platforms. That's mostly our bad, it should've been made more clear.