Here is the full list of all 14 Scrunk achievements.
Win a classic mode match
Win a free for all mode match
Achieve the rank of 'Wrecker'
Achieve the rank of Survivor'
Achieve the rank of 'Junklord'
Achieve the rank of 'Salvager'
Deal 3000 damage in one match
Get 30 player kills in one match
Destroy 100 blocks in one match
Destroy 30 mechs in one match
Scavenge 500 scrap from scrap piles in one match
Finish a classic mode match without dying
Get the first kill of the match
Get the finishing explosion off on the enemy's core