From the box:
"A fascinating game for two to four players. In three moves per turn, each player must try to match the color patterns on three cards to the colors on the playing board."
The game board features an inner and outer ring of indentations along with 5 colored balls and two decks of cards. For the easy game you use the inner ring, four balls, and the associated deck of cards. For the normal game you use the outer/larger ring, all 5 balls, and the other deck of cards.
Three cards are displayed at the beginning. The cards display the balls in various patterns (such as all colors sequential or colors in specific clumps with gaps between them, etc). On each turn a player gets three actions each of which he can use to relocate a ball. If at any time during the turn the balls match one of the card patterns the player wins that card (winning at most 3 cards per turn). At the end of the turn the display is re-filled to three cards before the next player starts their turn.
Once the deck is exhausted the players count their cards. The player who has won the most cards wins the game.