Here is the full list of all 12 Clatter achievements.
You were offered help but turned it down because you like danger.
Win your first ranked match.
Kill three units with one burner attack in a ranked match.
Get promoted to silver league in career mode.
Get promoted to gold league in career mode.
Make your commander sick.
Hit a commander with a projectile.
Score a goal.
Kill two units with a healer in a ranked match.
Kill all eight enemy units with your launcher in a ranked match.
Participate in the daily challenge.
Start a single-player campaign game.