Here is the full list of all 27 N++ (EU) trophies - there are 12 bronze, 7 silver, 7 gold and 1 platinum.
You are literally a ninja
Explore the Options menu
Beat the entire expert row of Solo Episodes
Beat the entire bottom row of Solo Episodes
Die 5000 times
Beat the entire middle row of Solo Episodes
Beat the entire top row of Solo Episodes
Kill another player using a rocket 5 times in a single MP Race episode.
Beat an entire column of Co-op Legacy episodes.
Beat an entire column of Co-op episodes.
Earn an All-Gold Badge in a Solo Episode from the bottom row
Die 1000 times
Beat an entire column of Race episodes.
Beat an entire column of Race Legacy episodes.
Get all the gold in the Solo Introduction
Die in every possible way
Watch a highscore replay.
Beat an entire column of Solo Legacy episodes.
Triumph over adversity
Beat a Solo Episode from the bottom row without dying
Beat a Solo Episode from the middle row without dying
Earn an All-Gold Badge in a Solo Episode from the middle row
Earn an All-Gold Badge in a Solo Episode from the top row
Beat a Solo Episode from the top row without dying.
Die 100 times
Die by hitting the ceiling too hard
Die during the solo introduction