Here is the full list of all 31 Fifty Words by POWGI (EU) trophies - there are 5 bronze, 22 silver, 3 gold and 1 platinum.
Collect all the trophies
Complete "Double-O Heaven"
Complete "Money Money Money"
Complete "Feathered Friends"
Complete "Too Many Cooks"
Complete "Ends With X"
Complete "Tee Time"
Complete "Got the Blues?"
Check the word list with only one word left to find
Find ZOMBIE 3 times
Find PARIS 3 times
Find MINT 3 times
Find MERCURY 3 times
Find EAGLE 3 times
Find DRIZZLE 3 times
Find DRIP 3 times
Find CHERRY 3 times
Find BOOTS 3 times
Find BABY 3 times
Complete a puzzle using 10 different colors
Complete a puzzle while only highlighting words backwards
Find all the diagonal words in a puzzle first
Edit the palette and choose 10 new colors
Zoom out for 5 seconds
Reset a completed puzzle
Review a completed puzzle
Complete a puzzle using only one color
Complete a puzzle without looking at the word list
Solve a puzzle in less than 3 minutes
Complete your first puzzle
Highlight a word backwards