Hard Difficulty
The most important thing to remember on this level is to minimize the Particle Cannons' collateral damage by spreading out your base structures - With how Laser Tanks require 1 power each, they aren't deployed frequently, so these weapons will provide most of the Laser General's offense. On hard difficulty, he starts with 3 Particle Cannons and the power to use them, forcing you to withstand their onslaught until they could be neutralized. Once that is done, it is simply a matter of time to build up an attack force and destroy his base.
Also, early in the game, there is an unguarded supply pile to the east of the map. You can send a dozer to go and build a supply depot there, but this expansion base is usually nothing more than a preferred target for Particle Cannons.
Start this level building two additional dozers. Remember to put a little distance between all structures and build your barracks, Nuke Reactor, and Supply Depot. At this point put up a few base defenses. You should build a bunker and a Gattling Cannon on the road near the tech repair bay. Then build the same on the road on the same diagonal to the northwest. For the most part, one of each along with a speaker tower(after they are available to you) should suffice until you can supplement them with an Overlord tank and/or a Nuke Cannon.
After your first bunker is built, start building a War Factory right away followed by the propaganda center, internet center (don't forget to fill it with Hackers and purchase the Satellite Hack ability later on) and nuke silo. Again, space them properly to avoid Particle Cannon strikes from obliterating several at once.
Leave some extra room around your Nuke Silo and build a speaker tower near it. Before you build a Nuke Silo, your perimeter base defenses and your command center are the primary targets of the Laser General's particle cannons. When you have a Nuke Silo it becomes the ONLY target of the particle cannons. When this happens you will want to keep a dozer next to it to repair it after every strike and the speaker tower will heal the dozer if it gets to close to the particle beam. The structure's odds of survival can be improved by building multiple dozers, such as if one is destroyed, another can immediately take over.
Because the Laser Tanks require 1 power each, they don't come in massive numbers, and most attacks can be easily fought off by garrisoned Tank Hunters/Red Guards and Gattling Cannons.
Once the Nuclear Missile is ready, combine it with a Level 3 Artillery Barrage back to back. This will finish all three Particle Cannons, and they won't be rebuilt in the foreseeable future.
By the time you are a 5 star General, your Nukes and your Generals Powers should have softened up his base a little. They should be target the Cold Fusion Reactor clusters next to disable the Laser Turrets and any remaining Laser Tanks, as Avengers fall very easily to Overlords, whose Gatling Guns can also take out Comanches.
You can start a frontal attack with a few Overlord Tanks (half with Speaker Tower and half with Gattling Cannon upgrades usually works fine - they'll heal other units and won't be completely defenseless if a Comanche comes around) Keep a Nuke Cannon or two behind the Overlords to destroy enemy Firebases that may harm the Overlords. Air Power isn't necessary because even with the Laser Turrets offline, Avengers and garrisoned Missile Defenders can still destroy them easily. Instead, simply switch to Neutron Shells and they'll be defeated in no time flat.
Alternate Strategy
This level is initially extremely intimidating. You start out with a Command Center and bulldozer – while the Laser General begins with three Particle Cannons ready to blast away.
The land assault starts slowly and this will give you a chance to form rudimentary defensive positions by garrisoning the buildings centered between your base and the Laser General’s base.
Build a solid defense, create Internet hackers and accumulate enough funds to build two Nuclear Missiles at once. This way, they are less susceptible to destruction while being built.
Build a few Gattling Cannons to the east of your base and possibly in the middle to deter Colonel Burton and Comanches.
Walkthrough
Basic start: Build a Reactor, an extra dozer, a Barracks, Supply Center. Build a second Supply Truck. Purchase Radar to activate the radar map.
Don’t forget to choose one of your General’s Powers.
Be sure that all buildings are placed far enough apart so that the Particle Cannons cannot destroy two buildings at once.
Sometimes enemy infantry occupy one of the five civilian buildings right in front of your base – and sometimes they don’t. Nevertheless, six garrisoned Tank Hunters can be used to brute force them. Add four Red Guard sand they'll be protected against any Infantry they could see.
Build a War Factory (if you haven’t done so already) and then the Propaganda Center so that you can build and park an Inferno Cannon in the center of the garrisoned buildings since the Infantry
Build a Speaker Tower in the middle of the buildings. Have a bulldozer in the area to keep the buildings repaired.
By now, the Particle Cannons will start attacking your base. At the beginning, “just” the Barracks will be destroyed. This is great, as you can constantly rebuild it for only 500 credits.
If it targets your Command Center, repair immediately or it will be lost on a subsequent blast.
Beef up your garrisoned buildings with five more Tank Hunters and five more Red Guard. This mission is “blessed” with a great bottleneck to protect your base. Take advantage of it. Add more units to these buildings as opportunity arises.
Build two Gattling Cannons to the northeast of your base, separated by a safe distance. You must keep these here to protect your base from Comanche attacks. They will be destroyed by PC blasts, but that’s okay. Just continue to rebuild them. The west side of your base will not be bothered by these attacks.
Consider having a second Inferno Cannon in the area of the garrisoned buildings to beef up defenses.
It is also necessary to be wary of Colonel Burton slipping onto your base and detonating your buildings. It is possible to mine your buildings to help minimize the threat. It also helps to putting a Gattling Cannon on the ramp leading down from the bridge to the east of the garrisoned buildings. Have a few teams of Listening Outposts and Gattling Tanks teamed up – just in case you have to go hunt him down.
A lot of this mission is two steps forward and one back with the constant repairing, but you will make slow but steady progress.
Build around eight to ten hackers and position them in different areas at the back of your base and have them start hacking the Internet for easy cash.
After you have over 9,000 credits saved, build two Nuclear Missiles simultaneously. This may prevent the PC’s from targeting your Nuclear two times in a row before it can repair and destroying 4,500 worth of infrastructure.
Once the Nuclear Missiles are completely built, attacks from enemy Particle blasts will not entirely destroy them and they can be repaired after each attack.
Wait for your PC’s to charge back up and you can then destroy the Command Center. When a bulldozer comes back to rebuild it, destroy it with an Artillery Barrage. As soon as all dozers are destroyed, no new structures can be built and you can slowly start taking the base apart.
Destroy first all Airfields, War Factories and Barracks.
Use your General’s Powers and armored units of your choice to destroy defenses at the very front of their base in case you decide to launch a ground assault. Or you can just use multiple nuclear strikes to finish the job.
Your ground forces have plenty of reach with the Inferno Cannon and Nuke Cannon, and the Overlords are supercharged.
It is not necessary to destroy the Laser Turrets, Fire Bases, garrisoned civilian buildings, infantry or vehicles to win the mission.
Once the frontal defenses are destroyed, a small ground force can perform mop-up duties of any structures left standing.
Mission accomplished!