Here is the full list of all 11 Cortex Command achievements.
Download 5 workshop mods.
Win The Tutorial Level
Watch the intro.
Boot up the game.
Win the metagame.
Win a metagame using every tech.
Save a preset with 10 crabs.
Fight 999 battles.
Win a battle with more deaths than your enemy.
Lose a battle with less deaths than the victor.
Release 500 crabs on your enemies.