How can I complete all "armory" achievements?

Question

I've almost completed campaign, bought all upgrades for infantry (and earned additional achievements, I don't remember it's name, let's name him "infantry armory achievement")... and discovered, that after "Gates of Hell" campaign there are no any income anymore...

I've tried to pass already existing missions another time, but they don't give money.

From what I see now the only option is to begin campaign again. Am I right?

Will my achievements be kept after campaign restart? I mean: don't I need to complete "infantry armory quest" again (and a lot of others too)?

Thanks a lot.

Answer 1

You are right, there is a limit to the amount of cash you can make during the campaign, so in theory you need multiple play-throughs to get all the armory achievements.

However, once you get achievements you can never lose them, so some people use some tricks like not getting any upgrades and just keeping the money, then saving, buying all upgrades of one type, getting the achievement, loading, buying all the upgrades of another type, getting the achievement, loading, etc. It's a very fast way to get all the achievements (including the master achievement) at once, but of course that way you won't enjoy any upgrades when playing the missions!

In any case, whether you take the long route of replaying the campaign, or the short but difficult route of saving and loading, you never lose achievements you have gained.

Answer 2

At first, the credits available to you in the single player campaign is limited to that from missions alone. However, once you've fully maxed out either the zerg or protoss research trees, you gain the ability to trade any future research points into 10k worth of credits.

There have been mentions of a glitch with the way the game handles this: if you replay a mission you've already beaten and acquire protoss / zerg research points within that mission, it is possible to get the Moebius foundation to "purchase research samples" from you, even though you failed to increase your net points (you already got them once). In this way, you can accrue as many credits as you need, and can buy all the armory upgrades in a single playthrough.

Update: This method has since been patched.

As of now, the best way to earn the armory achievements is to play the campaign multiple times, selecting different upgrades on each playthrough, as achievements are shared across all campaigns.