Here is the full list of all 11 Galak-Z: The Dimensional trophies - there are 7 bronze, 3 silver and 1 gold.
Unlock All Trophies
Complete Season Four
Defeat the Pirate King
Complete Season Three
Defeat 100 Space Bugs
Defeat 100 Void Raiders
Complete Season Two
Complete Mech Tutorial
Complete Intro Tutorial
Defeat 100 Imperials
Complete Season One