Here is the full list of all 27 Squeaky Squad achievements.
Pet the dog
Complete the Warful warehouse
Complete the tutorial
Complete the Pesky pipelines
Complete the Swarming sewers
Complete the dizzy deck
Complete the frenzy factory
Complete the Lunatic lab
Complete the Shifty skies
Beat the true leader of the Squeaky squad
Eliminate 1000 enemies
Spend 1000 coins
Spend 1000 gears
Buy everything from the hub store
Save all the crewmates
Die 25 times
Get 100 almanach entries
Get a 50 combo
Get a 100 combo
Finish a level without getting hit (excluding warful warehouse and shifty skies)
Finish a level under 15 minutes without using a shortcut (excluding warful warehouse and shifty skies)
Finish a level without getting an item (excluding warful warehouse and shifty skies)
Complete the Tense tunnel
Beat Mech Squeak for real this time
finish the game without diying once
finish the game under dev's best time
Win 100 wave battles