The difference is it sticks for the entire campaign once you buy it.
#SPECTER STARCRAFT 2 CAMPAIGN UPGRADE#
In the armory, you upgrade units that you would usually upgrade at a tech lab in multiplayer. You buy research upgrades in the lab or armory that aren't available in multiplayer: like allow a Command Center to build two SCV at once, harvest gas faster, add turrets to bunkers, etc. You can freely go from the Armory, Cantina, Laboratory or the Bridge.
![specter starcraft 2 campaign specter starcraft 2 campaign](https://guides.gamepressure.com/starcraftiiwingsofliberty/gfx/word/76608609.jpg)
Jim has his own ship, a Battlecruiser called the Hyperion. In times when the likes of Dawn of War II, Company of Heroes or Command & Conquer 4 removed the base building/resource+worker management elements, SC2 stuck to the original formula but spiced it up. I would have been happy with the original formula, but they brought it to new heights. there's three round, and achievements for losing under 20 and 10 units combined(all three rounds). so if you use all 10 marines against the mutas, you can't use them for any OTHER group of enemies. You have ti pick and choose which units you want to counter the zerg unit. One is a group of 6 mutalisks, one is an ultralisk, and the last is some of the brood things for zerg. there are three separate "groups" of enemy units. You start with 10 marines, 4 siege tanks, 8 marauders, and 6 vikings. You have to decide which units you want to use, and those units can ONLY be used on that one challenge. Like.the first one for each race gives you a handful of each units and puts you up against certain units of an opposing race. KIND of like the Spec Ops mission for MW2.
![specter starcraft 2 campaign specter starcraft 2 campaign](https://cdnb.artstation.com/p/assets/images/images/025/599/225/large/nak-ma-1586307101643.jpg)
and there's single player "challenges" as well. There's always something special about each mission, or some trick. There are hardly ANY missions where you just have to wipe out the opposition. I was a bit skeptical about it, but I've played quite a bit of it and I am really enjoying it.