Graphically, Eufloria is quite simple, with minimalistic graphics, and a simple design. The colour of your empire is customizable.
At the start of the game, the player has one tree on an asteroid which has a number of branches, and leaves which fall off and become seedlings, which can be used to either create trees or fight other seedlings. Each tree is unique, the growth of its branches based off a fractal algorithm.
To create trees, 10 seedlings are needed in orbit of an asteroid, which then plummet into the ground to grow grass and the trees' roots. A plant may also be grown that attacks invading enemy seedlings by releasing explosive fruit, called a defense tree. Over time, the plant's health, damage, and spawn rate increases. The player can also customize their asteroids with addons called 'flowers'. If a dyson tree has a flower added, dysons with a vastly enhanced firerate and range are produced. If a defence tree has a flower added, lasermines are produced. They are powerful seedlings which can take on multiple enemies with multiple lasers, and a suicidal explosion.
The seedlings can attack enemy asteroids, and take them over by burrowing through the roots to the core, and sapping the energy of the asteroid.
All levels are randomly generated, meaning each playthrough is slightly different. Also, each asteroid is unique in size and values, and produces seedlings with different stats. There are three stats. Speed enhances the moverate of seedlings, strength enhances the damage of seedlings, and energy increases the speed at which seedlings can convert enemy asteroids. The stats also affect the appearance of the seedlings.
Source: Wikipedia, "Eufloria", available under the CC-BY-SA License.