Also, this is what Sierra seys to do...
Easy Level
Mission Objectives
You must rescue the Scientists and capture the Gene Bank. Once acquired, they must be returned to the convoy’s starting location.
1)You must destroy all Advanced Labs and the Spaceport.
Tips from the Test Labs
Start at the Southwestern entrance to the Plymouth colony and go through it leaving nothing but rubble behind.
Use your EMP's and Thor's Hammers to quickly reduce Guard Towers. Keep your combat units grouped together with your Scouts, Cargo Truck and Evacuation Transport bringing up the rear. Put your Tigers in the front of your attack as they are the slowest and therefore set the pace. They also pack the biggest punch, and there is little that can stand up to a Thor's Hammer Tiger!
Make sure to Scout the Advanced Labs and retrieve the Gene Bank and Scientists before you blow them up!
Normal Level
Mission Objectives
You must rescue the Scientists and capture the Gene Bank. Once acquired, they must be returned to the convoy’s starting location.
1)You must destroy all Advanced Labs and the Spaceport.
Tips from the Test Labs
Enter the base via the entrance in the southwest corner of the map. The best strategy is to disable all of the Plymouth Vehicle Factories so that they can not manufacture more combat units. You can accomplish this in a couple of ways. You can Disable all Command Centers, thus disabling all other Plymouth structures. You can destroy all Power generation facilities. You can also try destroy the Vehicle Factories themselves. Once the Vehicle Factories are out of the way, the mission becomes a lot easier
Be careful of the EMPs and Spiders. Taking out the Arachnid Factories will help prevent losing your units to EMP/Spider attacks.
If you drop below a certain number of units, reinforcements will arrive. They also show up when you pick up the Gene Bank and Scientists. Any remaining enemy units will attack you at that point, so be ready to defend yourself.
Hard Level
Mission Objectives
You must rescue the Scientists and capture the Gene Bank. Once acquired, they must be returned to the convoy’s starting location.
2)You must destroy all Advanced Labs and the Spaceport.
Tips from the Test Labs
Enter Plymouth from the southwest. Use Thor's Hammer to take out the structures along the ridge, especially the Command Center and Vehicle Factory.
Watch out for vortexes in the desert and storms going across the map. Either of those can destroy your Cargo Trucks or Evacuation Transport, ending the mission.
Move carefully and slowly and pick off as many of the Factories and Guard Posts as you can without taking damage.
When you have picked up the Gene Bank and Scientists, all remaining enemy units will charge after those vehicles. Be ready, or even better, take out as many of them as you can before you pick up the last item.
Dropping below a certain number of units will bring in reinforcements that will head to your starting convoy location.