And Stay Down achievement Tip.

[Face United]

In Ch 6 after you take out the Brute in the transport hub, you come across 2 stationary plasma beams you will see an entity on the wall behind the 2nd beam that spits out little crawlers with a single tenticle. They take a second to open up once they land, so simply stand next to where they land and stomp on each one until achievement pops up. Hope this helps.