On the board are predators and prey.

The prey gain energy over time.

If two prey bump into each other, they can procreate and spawn another prey in that space.

The predators gain energy by feeding on the prey, and they can also procreate by bumping into each other.

You have a character that you can move around. By bumping into the prey you can absorb them and gain their energy, but if you instead absorb the predators you lose energy equal to their energy.

If you bump into another player, the player with the higher energy absorbs the lower energy. If you gain energy, you grow bigger, and move less quickly.