Here is the full list of all 30 Cannon Brawl achievements.
Defeat the enemy robot boss in Campaign mode
Destroy 250 buildings
Build 250 buildings
Defeat the enemy airship boss in Campaign mode
Reflection your laser off two enemy shields to damage another enemy building
Reflect your laser off an enemy shield to damage another enemy building
Defeat the enemy warship boss in Campaign mode
Damage Shield Towers 5 times by shooting around their shields.
Upgrade buildings 10 times.
Defeat Insane AI in Battle vs. AI mode without using shields
Win against the insane AI by selecting the warhead as your only attack building (Banks count as an attack build).
Rank up to ensign by playing multiplayer
Rank up to Lieutenant by playing multiplayer
Rank up to Commander by playing multiplayer
Rank up to Captain by playing multiplayer
Rank up to Vice Admiral by playing multiplayer
Rank up to Admiral by playing multiplayer
Rank up to Grand Admiral by playing multiplayer
Drop the enemy HQ in the water.
Complete the campaign on nightmare mode. You did it!
Defeat the enemy warship on nightmare mode.
Defeat the enemy airship on nightmare mode.
Destroy 4 buildings during one blasting of the Flame Thrower
Earn all 57 medals.
Destroy 500 buildings.
Destroy 1000 buildings.
Destroy 5000 buildings
Build 500 buildings.
Build 1000 buildings.
Build 5000 buildings.