Darwinia

Darwinia is a Virtual Themepark game, populated by a sentient evolving life form called the Darwinians.

Your primary weapon against the Virus is the Squad. With the help of Engineers, you can capture research, reprogram buildings, and collect souls. Most buildings in Darwinia are controlled by a nearby Control Tower.

You can use Engineers to reprogram Control Towers, enabling you to use the building that the Control Tower is connected to. Whenever a creature dies in Darwinia, be it a Darwinian or an evil Virus, it will leave a Soul behind. You may use Engineers to gather these Souls and take them to the nearest Incubator, where they will be reborn into Darwinians.