They're not so tough...
Kill 25 enemy Heavies
Terraforming
Plant 10 biomass seeding trees
Harvester
Collect 500 biomass from plants
Watch your step
Trigger an alarm in an enemy base
Lights out!
Disable your first enemy base
Next time try a larger gun
Kill 100 enemy engineers
All that sparkles
Collect 1000 rare minerals
Glug!
Have a unit drown
Grim Business
Loot 100 corpses
Unexpected bonus
Loot 50 weapons
Did you see that??
Watch an enemy unit loot an alien weapon from a corpse and equip it
What's all this then?
Find 5 loot crates in enemy bases
Recession? What recession
Loot 10 resource cache crates
Allied Tech Center
Reveal the whole world from a loot crate
Ding
Loot 5 promotions from crates
Aww nuts
Trigger a trapped resource crate
Pyromanaiac
Cause 500 secondary explosions
War Crimes
Plant 20 proximity mines
Putting the boot in
Kill and enemy unit with a proximity mine
Splenking
Reach the bottom level of the world
5 Star
Have a unit reach the maximum promotion level
Knifey spoony
Aim away from face
They Should Be Wearing Red Shirts
Kill 50 enemy soldiers
Resistance is futile
Kill 250 enemy heavies
None shall stand against us
Kill 500 enemy soldiers
Lambs to the slaughter
Kill 1000 enemy engineers
Oooh that was close
Lacking in all subtlety
Trigger 50 enemy base alarms
Cut the red wire
Disable 5 base alarms