Button Mashers

Button Mashers is a Duel minigame found in Mario Party 5 and Mario Party: The Top 100. It was also included as part of a Mario Party 5 demo found on a bonus disc bundled with preorder copies of Mario Kart: Double Dash!!

Gameplay
Players must try to avoid getting crushed by the blocks falling from the sky. To do so, they must quickly and simultaneously press every button shown on each of the blocks they are carrying. If both players survive for a few seconds, another block will fall, requiring the players to press two buttons simultaneously. If both still survive, another block will fall, making a total of three, then four, five, and finally six. After that, the player who stops pressing the buttons loses.

Ending
If at any time a player fails to press their button(s) quickly enough during the game, then that character gets crushed, making the opponent win the game. However, if both players get crushed at the same time, then the minigame ends in a draw.

Mario Party 5

 * Repeatedly and simultaneously press every button shown on each block.

Mario Party: The Top 100

 * Mash /////: Endure

Mario Party 5

 * Rules – "Don't let the blocks crush you. Repeatedly press each button shown on each block to keep from being crushed."
 * Advice – "Don't stop pushing the buttons, especially as the stack gets taller and taller and taller..."

Mario Party: The Top 100

 * Description – "Mash all the buttons shown on the falling blocks to avoid being squashed. How long can you hold out?"
 * On-screen – "Mash all the buttons shown on the falling blocks!"