Mario Clash is a Virtual Boy game, heavily based on the original Mario Bros., developed by Nintendo R&D1 and published by Nintendo. The game does not use polygons, like Super Mario 64, but instead 2D sprites.
The objective of the game is to knock all the enemies in a particular level off ledges. This is accomplished by hitting them using Koopa shells, of which there are always two—if one shell is knocked into a pit, another appears to take its place. The majority of Mario's enemies need to be hit on the side (i.e. with a shell thrown from the background while the enemies are in the foreground or vice versa). The player can choose to begin from any of the first forty stages.