The Amigo description is less than adequate.
Each player has a five card hand. On your turn, you discard a card (or cards... if they match) and then pick up a card - either from the draw pile or the open discard pile. Your objective is to reduce the points in your hand to 5 or below - but there are "jumper" cards (who can help or hurt) and a Lucky Number card that indicates that a certain point value is changed to zero for that hand.
There's also some other twists with the process for going out (calling "Bungee!") and with skipping players using "6" cards.