In the world of Treelings, construction is well and truly underway in preparation for the annual firefly festival! Beautiful, glowing swarms of fireflies may be released only from the highest towering platforms in the city during the upcoming summer solstice. Six different guilds reside in the city, and they will do everything possible to build their own tree as high as possible in each district. As chief of your district, each round you decide which guild you want to support in your part of the city as you want to lure the spectators to your show on festival day and to send as many brightly-glowing fireflies to freedom as possible.

In game terms, the guilds are represented by a deck of 108 cards, with each of the six guilds appearing 18 times. To set up, deal three cards face up to each player, grouping those cards in columns by color. Lay out five cards face up to form the market. Place the game-ending firefly festival card twenty cards up from the bottom of the deck.

On a turn, a player takes all the cards of one color from the market or one card of each color that appears only once in the market; they then add these cards to their collection. If you already have cards of that color, you place the new cards upward in a column so that everyone can see how many cards you have; if you don't have this color, place cards of the new color to the left or right of your current columns. Then refill the market. When the firefly festival card is revealed, end the game after each player has taken the same number of cards.

To score, look at each column of cards in your collection and compare the number of cards in it to the number of cards in the columns to the left and right. (For the columns on the outer edge of your collection, you compare their height to the height of your neighbor's closest column and the adjoining column in your collection.) For each column, if it's at least as tall as each column adjacent to it, you score points equal to the number of cards in that column. Whoever scores the most points wins!

—description from the publisher

One Hit Kill