Playtime is a two-player (or two-team) game.  A player pulls a slot machine lever.  A multiple-choice question, with a dollar value, pops up.  The player answers the question.  Correct answers win "money" and incorrect answers lose "money."  The player with the most "money" at the end wins the game.

Playtime is a great classroom review game.  The class is divided into two teams, each team with a captain.  After the captain (or teacher on behalf of the team) pulls the lever, the team decides upon an answer.  The captain officially states the team's answer.