The Escort level is Darwinia’s only hidden level. Access to the level is granted by capturing the Control Tower powering the Escort Trunk Port in the Generator level that is unmarked in the objectives and goes unmentioned by Doctor Sepulveda. Beating the Escort level is not integral to the main story line or progression of Darwinia, but it is most certainly fun to play, and will net you more research from the captured Control Towers.
The Escort level in Darwinia has one not so simple objective. Rescue 100 Darwinians stranded on the two small islands here, by escorting them through the central island with a massive viral infection, to the other side and the miniature Island with the Trunk Port and tree on it. This mission is almost essential that you have the Darwinians upgraded to at least version 3.0, although having them at 4.0 is even more preferable, as they themselves will be able to fight much of the virus threat with you supporting in this case.
Having the Armor battle cannon turrets from the Yard level will make this level ten times easier, however I will cover its though this is not available yet, as this is the way I completed it.
Start the Escort level by capturing the opposite Radar Dishes from the Darwinian islands. Spawn Squads and use them to start clearing out the virus threat, creating Engineers to scoop up souls to produce more Darwinians. At the same time, create Officers and start sending the little green army through the Radar Dishes.
Take your time in this mission, and use your squads to support your Darwinians during the Spider fights, or using their grenades to take out large batches of Virii. If you progress with caution, taking time to amass a massive force of Darwinians, you should have little difficulty cutting a swathe through the virus with a massive push to get at least 100 Darwinians to the other side.
The Triffids on this map may seem like a curse at first, but consider that they provide an endless stream of virus for you to turn into souls with your Squads to create more Darwinians. As long as you have a large built up force, the reinforcements brought by the eggs will be moot in stopping you from reaching the end goal here.