Here is the full list of all 22 Kingdom of Arcadia trophies - there are 4 bronze, 9 silver, 8 gold and 1 platinum.
Unlock all other trophies
Get the second magic scepter
Find 10 secret elements
Complete level 2-5
Complete level 2-4
Complete level 2-3
Complete level 2-2
Complete level 2-1
Get the first magic scepter
Find 5 secret elements
Upgrade your knife
Complete level 1-5
Upgrade your armor
Complete level 1-4
Upgrade your sword
Complete level 1-3
Open the first wall
Complete level 1-2
Find your first secret element
Complete level 1-1
Find a secret area
Destroy the first enemy