Here is the full list of all 43 Battlepillars achievements.
Earn 1,000,000 points in Hardcore Endless mode
Defeat General Battlepillar 20X7 in Endless mode
Defeat 2 bosses within 30 seconds in Endless mode
Complete every Gold Challenge and unlock the Gold skin
Defeat General Battlepillar 20X7 on the Moon
Unlock every skin in the Upgrade store
Complete 50 Gold Challenges
Complete the single-player campaign
Unlock Endless Mode
Defeat General Battlepillar 20X7 in Campaign Mode
Fully upgrade your base
Complete 40 Gold Challenges
Earn 5,000 apples
Defeat Geraldine the Scrap Queen in Campaign Mode
Unlock all segments in the Upgrade store
Complete 30 Gold Challenges
Defeat Frankenpillar in Campaign Mode
I didn't choose the bug life. The bug life chose me.
Make your multiplayer opponent concede defeat
Win a multiplayer match while at a disadvantage
Win 3 matches in a row during a single multiplayer session
Win a multiplayer match in under a minute
Win your first multiplayer match
Use an ally in a multiplayer match
Play an invite-only match with a Steam friend
Kill 50 spiders
Complete 20 Gold Challenges
Kill 1,000 enemy caterpillars
Unlock the Test Zone
Defeat Lieutenant Tikki-Tavi in Campaign Mode
Complete 10 Gold Challenges
Defeat Sergeant Flowerpuff in Campaign Mode
Use Larry the Bird for the first time
Build a developer Battlepillar
Purchase your first segment upgrade
Beat a level after your base has taken damage
Beat a level using only one type of segment
Beat a level using only single segment caterpillars
Kill 100 enemy caterpillars
Complete your first Gold Challenge
Keep your first deployed Battlepillar alive for the duration of a battle
Build your first 7 segment caterpillar
Complete the tutorial and beat the first stage