Project G

Project G is a Fighting Game created with Enterbrain's Fighting Game engine.

The titular Project G was a project intended to save the world from pollution. However, Regear, who was created to fulfill the task, decides to take over the world instead. What he does after that? Well, he travels 10000 years back in time so he... can take over the world back then, or something?

And guess what, Zero from the Mega Man X series is playable for some reason.

A review and more info can be found here. And this is the game's homepage.

This game contains examples of:

 * Amazing Technicolor Battlefield: One of the arenas.
 * Big Bad: Regear
 * Bonus Boss:
 * Combos
 * Game Breaker: Zero's "Spam Buster". if the first bullet hits, the move becomes unblockable, and you can keep shooting until Zero is out of power.
 * Just Here For Zero
 * Lawyer-Friendly Cameo: Zero, who is called "0" in menus and wields a "Omega Buster".
 * Doraemon is also involved in the story, but his face is censored.
 * SNK Boss:
 * Time Travel
 * Wasted Song: Hard Attacker Doll, which is used in the character select screen.