Megaman Universe, it was going to be the ultimate Mega Man game. It was going to come with a stage builder and character customization options so you can share a level and other creations online. It also added a ton of characters from other Capcom games and I'm sure more would have been added as DLC. Finally it was based on the Mega Man 2 engine but had modern 2D graphics. Which in my mind means it would have been the perfect Mega Man game since I love the classic series (Mega Man 2 and 9 are my favorites).
Capcom canceled the project and due to internal conflicts with Keiji Inafune he resigned his position. I personally feel he had no choice in the matter but didn't want to upset anyone so he resigned rather than begin fired for begin against the general direction Capcom was going in (releasing tons of DLC for SF4 for example instead of releasing it for free or creating new content/games).
Keiji broke off to do his own thing and started a kickstarter to make a game like Mega Man. Problem is so many people started throwing opinions his way about how the game should work. What I've seen of this new game is nothing like classic Mega Man. I'm pretty peeved that he caved so easily to these peoples demands. We shouldn't be cramming in politically correct characters and story lines just because some people get offended by anything. But I digress.
At any rate I was very excited for Mega Man Universe and it saddens me that we'll never get to play it. Here is some footage of actual game play. Anyone that loves side scrollers would have loved this game. Mega Man fans would have bought it in droves the day it was released. I don't know why Capcom abandoned the classic series when they were making so much money from Mega Man 9 and 10 at the time.
Wikipedia page about the game:
https://en.wikipedia.org/wiki/Mega_Man_Universe