Super Mario: Crossover World

 is a cancelled fan game, created by Mario Obsessed. It is a precursor to Super Mario: Crossover Explorers and was developed long before that game started. It didn't use the Gatate Mario Engine and was cancelled due to the creator's lack of passion for the project.

Gameplay
The game seems more streamline in terms of it's gameplay than it's successor: Mario, the only playable character, can run and jump like a traditional Super Mario Bros. title. The only gameplay footage available showcases no spin-jump.

Like SM:CE, the game has a P-Meter which the player can fill-up via running for a period of time. Once the whole bar is yellow, Mario will run faster. However, this prototype allowed the player to keep filling it up. Once the whole bar has become orange, he will run a little faster. This concept hasn't been carried over into SM:CE.

Another SM:CE feature absent are the CPU helpers that follow the player. Whilst Mega Man X, Miyuki Takara and Bowser are seen in the prototype, they serve no purpose but to be level decoration (and possibly interactable if the game had been developed further).

Trivia

 * Miyuki Takara's sprite is different from her SM:CE appearance.