Here is the full list of all 12 Black Knight Sword trophies - there are 7 bronze, 4 silver and 1 gold.
Finish the game without dying
Finish the game without ever entering the shop
Watch the end credits
Clear stage 5
Use a magic attack on the bread.
Clear stage 1
Read every tutorial board
Game over, 50 times over
Finish the game in hard mode
Clear Arcade Mode
Finish every mission in challenge mode
Collect all the cat head grass in story mode