It's a single-screen arcade platformer similar to Mario Bros. where the hero must reclaim a tower from Bowser's troops by jumping on Koopas and tossing their shells at other enemies. A stage is cleared once all enemies aside from the Koopas are taken down. Each stage has a foreground and a background layer, often requiring Mario to perform trick shots on enemies wandering on the opposite layer.
Mario Clash provides examples of:
- 2½D: The game is basically Mario Bros. with action taking place on a separate foreground and background, connected (of course) by pipes. Shells could be aimed from one into the other. The cancelled VB Mario Land
(which Mario Clash was originally a minigame from) also let Mario enter the background, and had top-down segments as well. - Bonus Level: One where Mario must collect coins that float foward from the background.
- The Cameo: Luigi, Peach and Yoshi appear among the audience of Toads in the bonus levels.
- Combos: You are awarded bonus points for hitting several enemies in a row with the same shell.
- Damn You, Muscle Memory!: Your first instinct upon seeing a winged Goomba will be to jump on it, but nope, they're also immune to stomping.
- Game-Over Man: Upon losing all lives, Mario's face will appear on the screen and inform the player of their final score.
- Goomba Stomp: Koopa Troopas are the only enemies that can be defeated by stomping; every other enemy including Goombas has to be defeated by being hit by the shells that the koopas generously provide Mario.
- Helpful Mook: Koopa Troopas. While they can hurt you, they're ineffective, and throwing their shells is the only way to defeat every enemy except them. Even the Goombas are tougher!
- The Spiny: Most enemies in the game are spiked and defeat Mario on contact. Some can only be whacked with shells tossed from the side, requiring Mario to constantly move across the stage's two layers.
- Tuckerization: There's an enemy called Lobb named after Ken Lobb.
- Turns Red: The last enemy remaining in a stage will become fast.
