The final mission is incredibly difficult, if not impossible, if you make certain mistakes that this contributor made. It can take days to complete. Of course, hindsight is 20/20 and you can do better with a few hints.
The onslaught starts right away. Immediately build a stationary gattling gun placement to defend yourself from the hoard of invaders that starts immediately.
Use the inferno cannon to immediately take out the rocket buggies on the top of the ridge.
Another mistake you can make, which can be a real pain, is building a building too far north in your initial starting area in the valley. Eventually Rocket Buggies will come and attack it later in the game when you don't need the distraction.
Carefully take over the base to the right. This is not a big issue.
Whenever you get a chance, build a good supply of hackers, as this will be your main source of income. Building at least eight would be much better than four.
Suggestion: Why stop at 8? The more you make, the faster you get money. Just remember to spread them out so they can't be killed with one strike.
It will be obvious to build a supply depot right by the supplies in the town you just captured.
Great idea gleaned from Staley: Capture the GLA supply center and use a hacker to hack additional funds from it before it is destroyed!
When you build your buildings, it is necessary to spread them out all over the map. You don't have to worry about defending them, as there is a bottleneck directly to the north of your small captured town. This is where the main battle will take place, to the north.
In the Allied final mission, the "Double-Nuke" strategy worked like a charm, but not on this mission. GLA has radar jammers, and you are never able to see anything worth nuking. Building double nuclear factories would be a waste of resources. This is going to be a ground war. The only way the nuclear capabilities could be used was as a way to slow down the onslaught of incoming troops.
Technique learned from Staley, Deuce ex Defcon: Slowly use a progression of Cluster Mines, Air Strikes and Nukes to slowly reveal the map to the north. Once this is done, the Scud Storm can be revealed and destroyed!
Approach the bottleneck to the north of your small captured town to face an onslaught of troops. It seems to never end.
Suggestion: A good way of defending is to get a small force of dragon tanks and make them form up in a line and start their fire-spraying attack. Keep a few tanks behind them in case any enemies get through and make your nuke cannons auto-attack in front of the dragon tanks. This way, you only need to worry about artillery and rocket buggies, which you can take out with a few MIGs.
When you get a chance, build another (or your first) weapon factory close to this area so you can repair your vehicles.
A main mistake you can make is not knowing you could upgrade your Overlord tanks with gattling guns.
It's very difficult trying to shuttle gattling gun vehicles and Overlords back and forth between oncoming troops and vehicles. Getting Overlord tanks upgraded with gattling guns will make things go much smoother.
Suggestion: An Overlord with a speaker tower on top will help prolong the life of your army greatly.
Plus don't forget to upgrade the Overlords with the two upgrades available at the nuclear facility.
The Scud Storm is a constant pain in the arse, and the key is to immediately save game when you got the launch message so you could move any vehicles and troops out of the way, if possible.
The "Oil Derrick" type buildings can be captured, but don't capture the oil derrick on the east side of town until you can defend that area, because they will come and destroy it immediately.
Have your Black Lotus up ahead of you so you can see what forces are coming at you.
It is a real grind working through the town, but for your peace of mind, once the town falls, it is just a mopup mission from there on out.
Instead of constantly trying to push through the center of town, once you pretty much hold the middle, it might be best to run a secondary force, once you build up the manpower, off to the left (west) and then up (north) and back to the east. This way you can wipe out some weapon factories and barracks that may help ease the constant barrage of troops coming at you.
Suggestion: Send in a nuclear missile or artillery barrage to help you destroy the town.
Maybe in hindsight building a very small air fleet might be worthwhile, just to uncover some of the map for you. The editor has not explored this method.
Suggestion: Building a few MIGs is a very good idea. It can destroy enemy artillery behind enemy lines and help your defences from time to time. Also, if you are not adverse to losing your planes, you can quite easily scout out the SCUD Storm and destroy it with your nuke and an artillery barrage.
Don't forget to use the electronic pulse general's power to disable attack vehicles and the cluster mine drop. You will need all the help you can get.
Suggestion: This is a slower but potentially more effective way to tackle this mission:
Note: Do not conduct any offensive measures too quickly. If the offensive fails, the enemy will send a counterattack to your base with twice the normal number of troops. If that happens, use 5 Dragon Tanks, deploy them horizontally in the base opening and use their Fire Wall ability, and use the Inferno Cannons as a guard. Use the Overlord with Speaker Tower as a healer for your defensive troops.
This alternate strategy also revolves around the use of the GLA supply center.
With your starting force for one of your overlords build a bunker, put any surviving infantry into it. On another build a speaker tower to repair your units. If your third one survives build a gatling gun on it.
In the starting GLA area to your right take out everything except the GLA supply center. Build a supply center of your own next to the supplies. Build a barracks and a propaganda center so you can build a Black Lotus and have her drain the GLA supply center of its funds. Once it is fully drained it will be captured. Build a worker.
Build the rest of your base, build hackers for money etc (as per previous strategies). Park your starting army on the slope that they charge up next to the second set of supplies over on the right hand side. You should easily be able to gun down their waves of attacks while you are up the hill. Once you get down into the town however it gets very cramped with restricted lines of fire, so you might want to stay up the hill for a while.
Once your economy is going well and you have some spare cash, start building the GLA buildings with your GLA worker. You can work your way up to building your own SCUD site and give them a taste of their own medicine! In order to find their SCUD site you can build a couple of radar vans and research the radar upgrade. Park them away from your buildings (so they don't get SCUD stormed) and (individually) hot-key them. C is the short cut key for scanning. Once you find their SCUD site you can throw your own SCUDs in their general direction plus artillery, nukes etc. Be lavish and remember that it is better to give than receive.
For fighting down in the city area they tend to throw waves of troops and light vehicles at you which are very easy to kill, but they also tend to have a lot of mobile scud launchers and those tend to decimate everything except air units and overlords. Even worse, they have a long attack range and so can attack you when you can not even see where they are.
To deal with that threat you can build groups of overlord tanks. Each group should consist of 5-6 overlords, upgraded with at least two speaker towers and at least two gatling cannons in each group. Technically one speaker tower is sufficient, but if they take out the overlord with the tower while your attention is elsewhere, then you may quickly lose the rest of the group too. So it is safer to have two in each group.
Before you take out their SCUD site don't bunch too many of these groups up (especially in the city area) because while overlords are relatively capable of dealing with a couple of hits from the mobile scud launchers, if they get hit by the scud storm they are too slow to move out of its area of effect and it will take them out.