Each turn in Iquaz, players either draw four cards or play cards of a single color from their hand to place one of their gems in an empty space on the board the same color as the cards they played. If you place in the leftmost column, you play only one card, in the secondmost left column, two cards, and so on. The last player in turn order adds a water droplet to the highest empty spot in the leftmost column after their turn.

 Iquazu on Boardgamegeek.com