About Showboat, from BoardGameGeek:
A new family card game played with an Island Deck, a six-suited deck of 54 cards. Because play is simultaneous, it doesn't matter if there is a single dealer, or if the job is shared between players.
Players play six hands, each consisting of several rounds. On each round, players will play one card and (usually) pick up one card from the center of the table. The played cards are collected into a tableau, which is a sequence of cards that is worth points at the end of the hand.
The player with the highest score after six hands wins the game.
Number cards are worth their face value, but only if they are larger than all cards played before them.
Face cards are worth five points each, and they do not follow the same ordering rules as number cards. They can be anywhere.
If your last card follows the ordering rules it scores double, unless you were the last player, in which case it scores normally.
Cards in your hand are worth negative points, unless they are duplicated in your hand, in which case they are worth zero.
The best you can typically score is 35 points, with three 5-point cards, one 6, and a doubled 7, as well as a zero point hand. This is called a Showboat.
