Here is a full Achievement guide for Creeper world 4 on Steam.
Lore, complete all story missions. Done via finishing Farsite Expedition tree
Reclaim, take over a certain amount of land, shown as a percent
Collective, gather the required item on the map
Nullification, successfully suppress all of the enemies on the map
Totem, active all of the totems on the map at the same time
Hold, keep an asset alive for the required time.
For an easy map do this on Shaka, expand right quickly and there should be sufficient power to hold off all fronts
Parallel Universe
Activate easter egg in 1st story mission.
Achievement image gives a big clue…
Play the first mission, the one where the alarm wakes you up, destory the HQ in the creeper.
21 Gun Salute
Activate easter egg in ‘Before Time’
Achievement image gives a big clue…
Go to the Span experiments, find before time and build 21 snipers. Mission finish not required
Farsite Farside
Achievement image gives a big clue…
On second story mission, connect the temple in the top right to the energy source in the bottom right