Collect all heart pieces on all levels
Pass all levels in time challenge mode
Die while frozen in ice
Retry a level 10 times in a row
Complete a level without collecting any heart pieces
Die with both characters at the same time
Jump 30 times in a single level
Complete a time attack level with exactly zero time remaining
Stay airborne for 3 and a half seconds
Complete all worlds in hardcore mode
Complete the first 10 levels
Complete a world in hardcore mode