Laboratory Research Upgrades
If you're having trouble with this tough achievement, selecting the proper upgrades from the laboratory before the last mission will help tremendously. If you have any regrets about the perks you've already chosen, you can always blaze through the campaign on easy and adjust the difficulty back to hard when you get to the last mission. These are the ones we think are most useful.
Above: To get the 'Aces High' achievement, you need to beat the final mission on the Hard difficulty and can only use this awesome artifact once!
- Strike Turret: This research perk upgrades all bunkers with a built-in turret, giving you a bit more firepower. We prefer this upgrade because it looks so much cooler than the Fortified Bunker upgrade. But our strategy will involve shielding our bunkers with a wall of Perdition Turrets, so we prefer the extra damage-per-second provided by the Strike Turret upgrade.
- Perdition Turret: You should aim to max out your army at 200/200 supply as soon as possible. Since resources are plentiful on this map, you should have lots of minerals leftover to continue building these defensive structures outside your base to act as a shield for your bunkers.
- Regenerative Bio-Steel: This perk allows your vehicles and ships to slowly regenerate their HP without any help from an SCV. You're going to be using lots of Siege Tanks, Banshees, and Battlecruisers to get through this fight. So anything that can help these units stay alive for a little bit longer will help you out a lot in the long run.
- Psi Disrupter: This structure slows down the movement speed of Zerg units by 50%. Placing a few of these structures outside your base will help increase the efficiency of your defenses. The alternative is the Hive Mind Emulator, which allows you to mind control any nearby Zerg unit. This can be helpful if used on Ultralisks, but we find that it's a little too difficult to make full use of the Hive Mind Emulator with so much chaos going on.
- Vanadium Plating: Armor upgrades purchased at the Armory or Engineering Bay will also increase the HP of units by 5%. Anything that can make your units live longer will help you.
- Micro-Filtering: Your Refineries will produce Vespene Gas 25% faster – and you'll need all the Vespene Gas you can get to quickly pump out Siege Tanks, Banshees, and Battlecruisers. But the great thing about this efficiency boost is that it also applies to the Automated Refinery, which we'll talk about next.
- Automated Refiner: Refineries no longer need to be manned by SCVs to produce Vespene Gas. Because of this, you can use an extra 9 SCVs from the very first second of the mission to start mining for minereals while your Automated Refiners produce Vespene Gas at increased speed (with the Micro-Filtering). Not having to build as many SCVs will also allow you to produce more units to defend your base with, as you will be aiming to max out your army at 200/200 supply.
- Tech Reactor: This is a must-have research upgrade, which combines the benefits of the Tech Lab and Reactor add-ons for your facilities. Upgrading your Barracks, Factories, and Starports with Tech Reactors will allow you to produce two high-tier units at a time and is absolutely necessary for maintaining and reinforcing your standing army.
Back at the Armory, we recommend picking up all upgrades for Bunkers, Marines, Banshees, Tanks, and Battlecruisers (if you can afford them). We also recommend upgrading your SCVs to repair faster and Terran Buildings so you can get an Orbital Command Center and the fire-supression system for your structures. In terms of mercenaries, we find it helpful to have the special Banshee, Battlecruiser, and Tank squads hired in case you need them.