From the publisher's website and the rules:
Described as "the card-flipping, risk-taking game", this is a card game whereas the other Farkle games are all dice games. The aim is to score 10,000 or more points (although with 6 or more players you can decide to play to say 5,000 or 7,500).
There are 110 cards - 14 each of 1-6, 22 Farkles and 4 score summary cards. A score-keeper is chosen. Each player is dealt one card BUT all players can play off anyone else's cards. The rest of the deck is placed in the middle of the table and each player takes it in turn to draw one card from the deck then place it in front of himself or another player. The goal is to create combinations that score (eg three 1s = 300 points, three 6s = 600 points, six of any number = 3,000 points, five Farkles = 2,000 points and so on). If you create a winning combination you can either slide it to the centre of the table for potential scoring or leave it where it is to try and build a bigger score. You can stop drawing at any time and score any cards you've placed in the centre. However if at any time you draw a Farkle card you MUSt stop drawing, any cards in the centre can't be scored and become part of the face-up cards in front of you. You keep your Farkle card to one side and no other players may take it but you may use it to score later. Farkle cards are scored whenever their owner chooses and are then placed face down. There are some other interesting rules about play. If cards run out all face down cards are shuffled and a new centre deck formed. First to 10,000 (or the agreed total) wins!
The publisher places no limit on the number of players.