Here is the full list of all 25 Linelight achievements.
Complete the Epilogue
Reach the end of World 6
Collect all World 6 Yellow Stars
Reach the end of World 5
Collect all World 5 Yellow Stars
Reach the end of World 4
Collect all World 4 Yellow Stars
Reach the end of World 3
Collect all World 3 Yellow Stars
Reach the end of World 2
Collect all World 2 Yellow Stars
Reach the end of World 1
Collect all World 1 Yellow Stars