As promised, Jay Pavlina has delivered Ryu Hayabusa from the NES Ninja Gaiden as the seventh playable character in the flash sensation Super Mario Bros. Crossover. Other character-specific abilities have been included in the game's 1.1 update.
Mega Man now jumps more realistically, and can use Rush Coil to get to higher spots on the level; Samus is equipped with crouching (and crouch fire); Simon Belmont has directional double-jumping; Link may attack up or down as he jumps. Bill from Contra is still too powerful and Mario doesn't change, but there are five difficulty levels and a cheats menu.
The full list of version upgrades can be found here, and the game is playable from the site's main page. Enjoy.
Super Mario Bros. Crossover [Exploding Rabbit/Jay Pavlina]