In fact, this game is slightly more than a card game given that it contains ten scoring tokens that are laid out to define the boundaries of a 5x5 grid. Each player has a hand of cards, with the cards coming in four suits numbered 1-7; one card is placed in the center of the grid to start play. On a turn, you place a card from your hand adjacent to a card already in play, and when the game ends you'll still hold one card. That's it!
Oh, wait, there's that small detail about how to score and win — you know, that detail that drives everything else that you do. At the end of the game, you determine which color has the highest sum in each row and column, with tied colors being ignored Raj-style; in each row, that highest color scores the points shown on the token sitting at left, and for each column, that color scores for the token above it. The card that you hold shows your color, and you score all the points that the color has scored, in addition to 1-7 points to match the value of the card you hold. After two complete rounds, whoever has the highest score wins.
Birdie Fight! includes rules for solo play in which your score equals the points scored by your color minus the points scored by all three other colors. Yes, you're one small bird up against an unfriendly world, so you'll need to set your enemies against one another to do well.