Evolve your creature far enough and you're onto the next stage, the Tribal stage. This is a simple RTS in which you either charm or destroy the other tribes through musical instruments or primitive weapons. This time you can use armour and other accoutrements to improve your chances, though you'll also spend much of your time hunting for or gathering food.
By allying with or wiping out your rival tribes, you can also access their technology, helping your creature move to the next stage: Civilization. Here your species has conquered the planet, but also splintered into a range of different cultures.
Your mission is to unite them all through economic and religious power or just your regular military might. You have access to some simple city building options, and also to fleets of land, sea and air vehicles that will defend your soil or blast other cultures from theirs. The key is to – in a nod to Dune – control the 'spice' that constantly erupts from volcanoes on land and sea.
Unite all the world's cities under your banner and you're off to the stars, and the Space phase. As a would-be captain in your world's interstellar navy it's your duty to accept missions from your leaders, negotiate with alien cultures and basically mess around with other planets and their indigenous fauna. In a way, the Space phase is the summation of all Spore's phases, allowing you to see what went before from a different, higher perspective.
Taken on its own, no phase is actually that complex, but if, say, the Civilization phase is simple it's an elegant simplicity. Sure, there's only one land unit type, one naval unit type and one air unit type per civilization, while facilities are limited to fundamentals like factories, homes and entertainment centres, but that's really all it needs to work and it makes the game far more accessible than a proper Civilization sim would have been.
The AI plays a decent game without being too tough on the easier levels, and at no point do you feel unfairly penalised for taking the peaceful option over the aggressive stance. If you want to breed herbivores who then go on to embrace religion or non-violent economic methods, that's fine. If you want to create the most aggressive predator in town then turn them into the ultimate warrior race, that's fine too.
Even more than Black and White, Spore provides you with ways to play with different choices and objectives, and there's always a strong feeling of causality and biologically anchored advancement – the choices you make in the Cell and Creature phases will be reflected in the Tribal and Civilization phases, partly because they define what special abilities you'll be able to call upon in combat or diplomacy.
At the same time, your creature isn't totally defined by what has gone before. If you start off with a creature that's all claw and spiky tail, they don't necessarily have to become an aggressive culture, though the pros and cons latent in their biology will certainly promote that kind of behaviour.