The game is named after where it starts: the "watery muck" where life begins. This is, as we know from previous articles, the place where you have to eat smaller bits and avoid bigger and badder ones, until you lay an egg and grow up. By clicking that egg, you see the editor for the first time. You see a 3D model there, where you can move and rotate it, but of course also adjust it. For every generation some new options will appear. By spending life span points you can add extra features and such.
As has been told before, they also highlight that the movement of the creature is linked to how you design your species. Every creature that was shown had a plausible way it moved. But after a few generations, when another egg is laid, you can't just change the parts of the animal, but you can also adjust its size and shape. You can add textures like stripes and spots if you want too.
The online aspect is of course also mentioned. Having your creatures uploaded is an optional feature, so it can be turned off. Downloading will be necessary to populate the world, as the game will try to fill the ecosystem so there are creatures to match the environment. When you teach your creature to kill another, you can also teach them to drag the prey.
Once your creature has formed a tribe, with some help of course, they will start forming a small society. News is that you can drop something next to them, and the tribe members will jump up and down and run to the object to examine it. Your tribe is not alone, but across the planet there will be more groups of your creature.
After starting a city, you can place buildings for certain (mysterious) purposes. IGN says it could be factories or food plants, like any RTS game has. Your buildings will, if you want, be uploaded to the master server as well. The same goes for vehicles your civilisation will create. Those too can be designed to your liking using the editor. After a while, your task is to "bring the planet together," either through "diplomacy, trade, or beating the other civilizations with a stick and taking their cities from them."
The UFO that you develop eventually has one feature not mentioned before: an abduction beam can collect speciments from planets. It can be used to find out if a planet is habitable or not, but otherwise it's a bit unclear what can be done. You can create cities on any planet, regardless of the atmosphere, as they will be protected by bubble domes. You can also activate volcanoes to create an atmosphere on the planet, which can be done through an upgrade of your UFO. You can also buy a "genesis device" which can instantly create an livable atmosphere on the planet.
Finding new life in the galaxy can be done using a radio telescope, through which you'll scan the galaxy. New life can so be detected. You can try to bring your UFO in contact with creatures on other planets, but it may also be necessary to blow up the entire place to keep your UFO flying. There are enough other planets and galaxies to fly around to and fro. Read the preview for IGN's exact words about Spore.