Back in 2012, when I still played Flash games, I browsed the website and found a game called Contra: World Challenge. Its preview image was very small, but I saw a location resembling Green Hill Zone and a semi-blue figure.

On the game's title screen, there was also a tiny icon of spinning Earth, though its continents were pale green, almost white, which made me think this is Sonic Spin Dash.

However, when the game has started, I understood this isn't a Sonic game, though it was still interesting. The protagonist was also capable to do the Spin Jump, except it wasn't an offensive move.