Heart of the Swarm Campaign- Umoja Achievements: Rendezvous

Normal Difficulty:

Rendezvous (10): Complete the Mission.

First Strike (10): Destroy 15 enemy structures before Naktul's forces arrive.  This can only really be accomplished by taking out the Terran base guarding the Northeast cave before the timer runs out.  Not a tough challenge, but if you're taking a more relaxed approach to this mission, it can elude you.

Zerg Save the Queen (10): Rescue all three queens within the 15 minute wait.  This is actually easier than First Strike, if only because you don't have to destroy the entire Dominion outpost to reach the third cave.  If you're angling for just this, a close rein on your attacking force can get you this achievement before or even without First Strike.

Hard Difficulty:

Premature Evacuation (10): Destroy all Dominion structures before Naktul's brood arrives.  This puts a lot of pressure on you- even in Normal difficulty, those who aren't adept at micromanaging will find this condition difficult to meet- if you can't do a lot of micromanaging, don't expect to accomplish this one at all: your units won't survive the rush well enough to pull it off.  Key here is the proper combination of queens and zerglings to keep as many units alive as you can while not losing too much firepower to the queens' weaker attacks.  Thankfully, this only includes the buildings surrounding the three caves that the Zerg locals are trapped in, as you don't get access to the other Terran bases until after Naktul's brood arrive.