In more detail, the deck contains cards numbered 1-100, and during the game you try to complete 12, 10, or 8 levels of play with 2, 3, or 4 players. In a level, each player receives a hand of cards equal to the number of the level: one card in level 1, two cards in level 2, etc. Collectively you must play these cards into the center of the table on a single discard pile in ascending order but you cannot communicate with one another in any way as to which cards you hold. You simply stare into one another's eyes, and when you feel the time is right, you play your lowest card. If no one holds a card lower than what you played, great, the game continues! If someone did, all players discard face up all cards lower than what you played, and you lose one life.
You start the game with a number of lives equal to the number of players. Lose all your lives, and you lose the game. You start with one shuriken as well, and if everyone wants to use a shuriken, each player discards their lowest card face up, giving everyone information and getting you closer to completing the level. As you complete levels, you might receive a reward of a shuriken or an extra life. Complete all the levels, and you win!
For an extra challenge, play The Mind in extreme mode with all played cards going onto the stack face down. You don't look at the cards played until the end of a level, losing lives at that time for cards played out of order.