There are two flavors of multiplayer: coop and versus. The gameplay is the same as the single-player game, which includes sharing the same screen. Each player selects a color and starting character, and is then assigned an area of the screen to control their character.
In coop, everyone works together to reach the end of a level. Characters lost during the level will respawn when another player activates a clone power-up.
Versus mode is a survival race that uses distinct levels. You win by either reaching the end first or being the last clone standing. Power-ups are absorbed by the first character that reaches it, and the effects are not shared.