The aim of the game is to have the most species points at the end of the game. Species that are living in habitat at the end of the game give you species points - the more endangered the species the higher the points (it ranges from 1 - 4 points per species card)
Players take turns playing. On your turn, you have 3 choices, and you can only pick one
Pick up a card from either the biome deck draw pile or biome deck discard pile, and then put a card on the discard pile, so they remain with 7 cards.
Create a biome by playing down at least 2 habitat cards, and at least one species card of the same biome type.
Add to a biome, by placing at least 2 cards (species or habitat) of the same biome type next to one of your biomes.
When someone does option 2 or 3 they must pick up as many cards as they put down from the draw pile or discard pile. Then they must draw an event card and follow the instructions
Event cards can do things like:
Destroy habitat (species with no habitat become extinct and you lose their points)
Give you extra cards
Allow you to steal cards
Give you bonus national parks
And more...
The game ends when there are no cards left in the draw pile and discard pile. Everyone counts up their species points and whoever has the most wins.
—description from the designer